Or, rather "I don't know if I agree that MVP's need to work well or even at all for over half the people using it."
That's what you're saying if you decide not to support the current most popular web browser. Like it or not, you need to build things for the platform your users are on. If I were building a product, I'd make sure it works in IE first and foremost before worrying about niche browsers like FF and Chrome.
Just because 100% of the people here use one of those two "niche" browsers as their main browser, don't assume your users will.
First, over half of people do not use IE8, so not sure where that stat is coming from. Second, not sure I'd call FF or Chrome niche.
Not paying too much attention to IE (IE8 specifically) is a strategy worth doing. It's a pain in the ass to support IE8 and not worth the extra development time in the short term. Plus, not sure if this applies to this startup (I'd say it does), users like those in HN (the majority of whom use FF or Chrome) are the users you want initially to use and support your startup. If they like it, they become quite the dedicated user, which really helps to get your startup off the ground initially. So targeting FF and Chrome users is hardly a bad strategy for release 1. Adding IE8 in the mix is way more frustration than it's worth.
Would it make you happier if I said 1/3? Is that a reasonable fraction of your potential userbase to leave with a bad impression of your business?
You make it sound like supporting Internet Explorer is difficult. If it's 2003, then yes, I'll agree with you. But today it's not.
Supporting IE in 2011 is a matter of building your site against Chrome while not going out of your way to use non-standard things like Object.keys, localStorage or Canvas when you can avoid them. Then you test on IE7, notice your corners aren't rounded, and decide you can live with that.
If, on the other hand, you go out of your way to cram in as much HTML5 nonsense as you can fit, or refuse to spend a few minutes getting IE to render, you need to realize that you're not taking a stand. You're just being lazy.
But then at the end of the day it's your business, so you're well within your rights to be lazy. You may or may not make less money as a result, but then again that's nobody's business but your own.
That's what you're saying if you decide not to support the current most popular web browser. Like it or not, you need to build things for the platform your users are on. If I were building a product, I'd make sure it works in IE first and foremost before worrying about niche browsers like FF and Chrome.
Just because 100% of the people here use one of those two "niche" browsers as their main browser, don't assume your users will.