Sure. Like I said, if you're actually measuring it, then that's one thing. But supporting older browsers usually isn't that hard if you know what you're doing. Obviously there are some features that you just can't backport and there's not much you can do there. But more often than not I read comments like "as a policy, I just won't support IE < 9."
In any event, the cost argument is the purview of the business owner perspective, not the Web developer. And it's hard to look at in isolation. I don't know that many sites that wouldn't love to have another 5% of traffic. Yeah, it may cost more to support older browsers, but driving traffic to a site costs money, whether through ads or spending time on inbound marketing. Trying to bump conversion rates on your existing traffic costs money and time as well.
There's obviously a balance to it. At the extreme end, I know of businesses that support anything with > 0.5% market share because at the volume they operate at, it's worth millions. At the other end, I see startups fight tooth-and-nail working on their funnels, while throwing away legitimate sources of revenue.
It's rarely all-or-nothing. For me "not supported" means that the site wasn't extensively tested on a given browser or it doesn't offer full experience, not that it doesn't work at all. Another issue is whether those enterprise IE6 users are really the target audience of your startup.
Anyway, it seems like we both agree that it should be a deliberate decision.
In any event, the cost argument is the purview of the business owner perspective, not the Web developer. And it's hard to look at in isolation. I don't know that many sites that wouldn't love to have another 5% of traffic. Yeah, it may cost more to support older browsers, but driving traffic to a site costs money, whether through ads or spending time on inbound marketing. Trying to bump conversion rates on your existing traffic costs money and time as well.
There's obviously a balance to it. At the extreme end, I know of businesses that support anything with > 0.5% market share because at the volume they operate at, it's worth millions. At the other end, I see startups fight tooth-and-nail working on their funnels, while throwing away legitimate sources of revenue.