With so many pools I flipped through a few different logins. I was not aware of easy to use password generators that store passwords for you, like lastpass or the one you mentioned. I have been altcoin mining for over a year now and never had a problem, until I did.
Now I will use lastpass for everything. Scammers suck!
I didn't use the same info for every pool, but after using 100's of pools, yeah some get reused.