I don't get what all these rants are all about. I've been using plasma 5 since 5.2 came out with no problems whatsoever. Just a few hours ago I've updated to Plasma 5.3.1 and KDE apps 15.04.01 and stil no issues.
So instead of posting comments like:
" Kubuntu made a dire mistake in releasing Plasma 5", "That's how long I could stand the buggy OS", "15.04 is in really really bad shape", " Kubuntu 15.04 the worst idea in the history of Kubuntu", why don't you file some bug reports?