I think you overestimate the power of the Liqua!
Don't get me wrong I really like him and he's certainly added a great deal to these forums and the DDF over the last two years... but, let's be honest, if he hadn't taken the 5k pledge tier somebody else would have, and I'm sure he'd be fairly incredulous if FD decided that the game lived or died on his opinion.
It's not the first time that some of the higher tier backers have stormed off over some perceived (whether real or imagined) sleight by FD, mostly to return later, and no doubt it won't be the last.
Still he isn't any backer... He is the highest tier backer. Paying 5000GBP must count for something right? At least more than "Let's hear the crummy name you want that system to have. Don't sit down, you won't stay long enough for that. Now shut up and get out, rube."
And this isn't a slight, this is the dropping of a solid feature a month before launch, a feature that was used as a buy-in insurance right up until FD canned it.
And in another perspective: People are so afraid now that their pet-feature won't make it in that I read lines like "It can come back after walking around your spaceship has been implemented". Hmmmm...