Browse host is pretty unreliable anyway. You have a better chance of being able to browse someone if they have chat enabled (you'll see a smiley). Even then it's unpredictable... one minute you can't, next minute you can

There are probably lots of people who aren't aware that enabling chat makes it easier to browse. It doesn't mean they're not sharing! It's so hard to tell if someone's a freeloader (not sharing), I don't think there's any definitive way of finding out