Although I bought my WR-250X used and the tires were well-worn, I didn't think they were terrible.
I could see somebody putting another set of BT090s on once the originals wore out.
Myself, I feel that at least some of the riders out there will automatically claim the stock tires suck, no matter what they are or no matter what the bike, for that matter.
Also, I can easily see somebody wearing down the stock rear tire in 1,500 miles of use - what was left of my original BT090 when I got the bike didn't last too long at all.
All it takes is plenty of hard acelleration, braking, etc.
Even worse, the stock Dunlop D208SM tires that come on my 2009 Suzuki DR-Z400SM were down to the rear wear bars by 1,300 miles.
I bought another D208SM rear because the front was still decent, and that one went 1,300 miles, again.
Six weeks of street use, in fact.
Michelin Pilot Powers last longer and grip much better, so those tires are really something else. :)