Supporting Firefox and IE are decisions. I choose not to do it until something I've built had had consistent usage for a few months. Then I spend the time and support them but it's a pain. I test on chrome and safari web and mobile (blankslate is not a good mobile experience mind you). I'll jump in and fix the known Firefox layout weirdness soon but it's not laziness, it's a choice. Instead of doing that I built a google docs integration and PDF converter, I felt that was more worthwhile. You don't, that's fine.
As for the commenter saying he hacks my stuff, he has told me the problems and I appreciate it as I always do. He's always been a dick about it for some reason but that's his prerogative. I hope he keeps hacking what he thinks of as my projects (almost everything he's hacked before was something I was either re-coding or didn't code at all).