Effectively critiquing ideas without hurting feelings is a powerful skill, hard to master, and shouldn't be written off.
IME there are only 2 reliable ways to get people to do what you want: you have authority to tell them to do it, or you can convince them that it's the best course of action.
People often treat their ideas like their children - and calling someone's child "stupid", or "braindead" isn't going to make you popular with them. Good luck convincing them it's a bad idea now - it's a matter of pride, and they'll obstruct you every way they can. Is this rational? No - but it's a reality of working with people, and denying it is futile. I've done it myself in the past, without being aware of my biases, and even then I'll probably do it again in future.
If you're actually working with people (and those people's bosses) who can't be reasoned with using facts and data, presented without calling the idea names, then the rational thing to do (which, it seems, you did) is to find a different team or company. Either you're wrong or they are, and time will prove someone right.
> Who was insulted? What parts of the comment were insulting?
I read the comment and my opinion is "It's a CSS framework! How can it take over a year to make?!" and "The speed and quality of development leaves much to be desired. For example: It took them five months to merge a TTY component. We wrote a similar component in two days." might have been the insulting parts.
Those comments could be construed as calling those devs slow and incompetent. I don't know if that was your actual meaning, but it's hard for me to read it any other way - sorry :-( maybe I'm missing some context.
Sorry also if any of what I said seemed rude. It took me years of insulting people to learn this stuff, and I'm still nowhere near perfect :-), but I thought I should share - it's possible I'm wrong. I also understand if you feel differently.
P.S. I checked out Floobits and it looks super-cool. I'm looking forward to trying it out sometime.