I understand the spirit of the developer's response and yes, there is a difference between an amateur and a professional developer. Developers likely start out with lots of ideas, but have to downsize due to the context of budget and time-frame. So when some "super-fan" shows up and says that your hard work and effort sucks, here's how I would do things way better, the developer has a right to be offended.
But Gerry Pugliese does not speak for all "armchair designers".
Take BelatedMedia's "What If" take on the Star Wars Prequels. It's universally agreed that the films were inferior to the original trilogy and each episode had inherent problems with characters, plot, setting, and etc. But BM isn't trying to say that George Lucas sucks as a writer and merely did their "What If" Takes for recreational exploration on how to make the Prequels not suck that takes George's concepts, themes and ideas and tweaks them so that the theoretical films would have more life, substance and cohesion to them.
As far as the developer's comments on a finite budget are concerned, why isn't "so and so" possible? How come BW had a budget to give Liara, Ashley and Kaiden a legit love scene, but Garrus, Tali and other LI's were only given "Fade to Black" scenes? How come the former three characters were given more budget priority? How come you had enough of a budget for StarChild, but not for a true utilization of the War Assets? How come you had enough of a budget for Rachni Queen Clone, but not for Tali's face? Or enough of a budget for Kai Leng, but not another squadmember?
I won't pretend to know everything that happens in Game Development and I see what the developer is saying. But if a game like Colonial Marines, Soul Calibur V or Sonic 06 sucks, then why shouldn't someone be able to make up their own private alternative that asks, "What If this game/movie didn't suck?" It won't change reality, but it's not doing any harm to that developer's earnings and chances are, most people won't even read it.
Or how about "Armchair" Reinterpretations that focus on story rather than actual mechanics of gameplay? Especially if it's a terrible story like FFXIII or the endings to ME3 or even that Spiderman Comic: One More Day? I somewhat view this as more akin to a restuarant customer who sees a hard-working chef, tastes his food, doesn't like something in it and asks why it can't be prepared in another way or why it doesn't have a certain ingrediant. That's not to say that the chef is terrible (unless he really is that bad, in which case he'll be fired soon anyway), but customers do have a right to ask questions about the food that they're paying to eat right?
Now without the context of budget, time restraints or clashing team vision then amatuer writers/fans don't truly understand game development or it's hickups. But that doesn't make all of us spoiled and self-indulged losers who think that we know better. I won't pretend that some of us aren't, but does that mean we can't be critical of something that sucks or try to make something better even if only to appeal to what we personally wanted from whatever turned out to suck and for no other comercial gain?