... or webdevs/companies who continue to support legacy platforms (and thus not force people to update). Clients are clueless anyway.
I don't know about you, but I certainly can't afford to throw away 100k every year.
When reporting issues I often say "Can you upgrade your browser?" to which I get the reply "No, it's what the IT department put on all of the machines, I use (BrowserX) at home though."
I suspect this is common.