Who is the "we", you're referring to that are aiming for this? Yourself and those with a likeminded ideology. Though I'm all for cybernetic and other technological augmentation of the organic body to increase its capablities, I've no desire to rewrite my own DNA, play with my neural architecture and kill my previous consciousness (which is what Synthesis does, given the way it alters the very nature and thought processes of organics), nor do I think I have the moral authority to unilaterally decide those sorts of things for centillions of sentient, sapient beings until the end of time.
It does exactly that. The energy of the Crucible is combined with Shepard's "organic energy" (whatever the frell that means) to create "a new framework, a new DNA" for every organic lifeform in the galaxy down to at least plantae. It is objectively a loss in diversity. Whether or not you think the relative amount is justifiable is up to your system of morality. Mine doesn't, because there was no need to get rid of said diversity in the first place unless you ascribe moral rights to toasters (I don't) and therefore don't want to simply control and destroy them with the Crucible every time they rebel for the rest of history.
Precisely, which is why I would not cross that stone wall without first devising a means of gathering sufficient information on what is on the other side, as it could be anything. I certainly wouldn't jump headlong onto the other side/into the beam with almost zero elucidation as to what the nature of the other side even is.
We as in humanity which you are a part of. If ever the cybernetic enhancement even the rather over the top version out of Metal Gear Rising: Revengance type stuff. Every government that could create soldiers like that would do it in a heart beat. If the world was offered a more realistic Ghost in the Shell style upgrade. Even the most basic one like Togusa has they would take it.
If you want to be technical every single child born rewrites DNA. Hence why we each have our own DNA sequence and why it can be used to identify suspects in crimes. Like wise cancer is a form of DNA alteration. Cells reproducing endlessly rather then just replacing older dead ones then stopping. Changing how it is created and what makes it up doesn't remove diversity. As long as reproduction is formed by combining the DNA of two parents diversity of DNA will remain.
Altering how the nature of thought process again isn't striking me as bad. I need only look at the history and logic used not only by humans but even by known information about the other races in ME universe to see the logic used and how their thought processes were used came up short. Seriously how many people have died in the past due to lets say less then intelligent thoughts? How many times did a single/group of ass holes manipulate large sums of people to kill others because they think they are doing their God's work? How many people have suffered from violence simply because to another group they were different. And in the aggressor's mind them being different is bad? Do you not know the almost borderline torture humanity has pulled on people with mental disabilities? Seriously up to the 70's it was legal for the state to medically castrate any mentally handicapped person. I can't even comprehend that kind of fucked up logic.
Human history past and present is so full of **** up idiotic logic it proves without a shadow of a doubt there is no God in any form. Because no divine deity would put up with the sheer amount of stupid bullshit we have pulled. Hell there are days I wish we were fire bombed from existence for the stupid bullshit we pull. So if you are going to use a point against synthesis. Then changing the fundamental way we think isn't the best reason to go with. Because the fundamental way we think has lead to pain, suffering, violence and death more times then anyone can count. And even in the ME universe nothing seems to have changed.
Moral authority is a weak and sad argument. No one has the moral authority to even make the conscious choice to try to have a child with their wife/partner. Heck you don't even have the moral authority to decide to spay/neuter your cat. Moral authority is such a weak argument because it varies day to day and hour to hour. What gives judges the moral authority to give people their punishments? Because a bunch of other people decided he was a bad guy? What gives them the moral authority to decide that? A dictator killing anyone who dares question his rule feels he has the moral authority to do so. The guy on the other side of the world reading about the acts feels it is within his moral authority to claim that it is wrong to be done. Who is correct? What gives you the moral authority to come to that conclusion?
New frame work doesn't mean everything is going to be the same. That is your interpretation of it. Again altering how it forms doesn't mean it will all form the same way. Evolution is based on altering how DNA forms to create new creatures who's useful traits get passed on while less useful ones die off. Human and chimps are very similar in many ways. How ever our DNA is vastly different. Incompatible to the point that even though we both reproduce the same way there is no way for a human/chimp hybrid to ever be born. Our DNA is different due to the different evolutionary paths taken. Altering the DNA of both species as we evolved to the point they are incompatible with each other.
The problem is you can not comprehend what is on the other side. It is like plucking someone from Ancient Mesopotamia and dropping them into modern day and expecting them to understand everything. Things would change in so many ways you wouldn't be able to make the claim of it being correct or not. The rules that exist for chess don't exist for checkers. And that is in a nut shell what synthesis would do. Alter the game from chess to checkers.
So you sitting at your chess board. Having only ever played chess. It is all you know all you understand. Then someone puts a game of checkers next to you. You can't call any rules on it. You can't decide the winner or loser of the game because you fundamentally don't under stand it.