Windows ME was a crapshoot. One of our computers blue screened a few times during the couple months we had it installed; the other couldn't even run an hour without hard crashing.
Nowadays I can't even remember the last time Windows crashed. Newer versions are definitely a lot more stable, though suck in different ways.
8 changed a lot of UI for no reason other than to chase the mobile market. 8.1 reverted a lot of that and people liked it, but the damage to 8's reputation had already been done.
If they kept the edition alive for a few years 8.1 might be remembered as a redemption story like Windows 98 Second Edition, but they rushed 10 out the door - as a free upgrade, no less - to get back the goodwill they'd lost.