Synthesis is being forced to give up your old identity and assume a new one. Because organics are not worthy of existing.
The bolded is an unnecessary and provocative exaggeration, but the front end is generally correct on a fundamental basis. However, studies show that our genetic framework changes over the course of our lifetime anyway, effectively changing our identity by that base definition, too. Our physical composition isn't the bottom line in who we are, and I'd argue that the people seen doing the same things in destroy and synthesis universes---as presented by BioWare---retained their "identity". And yeah, there are going to be tons of people who would eat the benefits of synthesis, in the positive interpretation of it, up with a spoon.
Just a few musings from an avid destroyer playing devil's advocate.