I'm a Firefox user, working exclusively on Windows (although a Linux nut by night).
If a site blocks any browser by user-agent _and I find out about that_ (as a user of FF that's not a regular case) that site is dead. I will create some childish rhymes about the creator of that thing, I'm going to compare it to acoustic couplers or pay phones and .. move on.
There are good reasons to avoid supporting every browser and the IE brand _had_ (and has) problems.
But user agent sniffing? That results in one reaction only (again, of course, limited to 'what I can notice'):
This business isn't able to provide a usable web presence. I'm going elsewhere.
> This business isn't able to provide a usable web presence.
Define "usable". It's certainly usable if you are not on IE and, if the resources they'd use to support IE in addition to others are diverted into new and useful features, I'm happy.
Even if you use feature detection, you'll still have to test on IE (and, to do it right, you'1l have to test on a matrix of 3 or 4 OSs (XP, Vista, 7, 8) and 4 browser versions (7, 8, 9 and 10). If IE breaks, you'll still have to fix it in ways other browsers don't break. That costs money.
If a site blocks any browser by user-agent _and I find out about that_ (as a user of FF that's not a regular case) that site is dead. I will create some childish rhymes about the creator of that thing, I'm going to compare it to acoustic couplers or pay phones and .. move on.
There are good reasons to avoid supporting every browser and the IE brand _had_ (and has) problems.
But user agent sniffing? That results in one reaction only (again, of course, limited to 'what I can notice'):
This business isn't able to provide a usable web presence. I'm going elsewhere.