Other than MicroSoft, they are the most bloated, resource consuming and intrusive Windows software out there.
Some of their past bugs have been notorious, and some of their new ones are insidious.
It doesn't help that I have a crap laptop with a crap processor (i3) but still... Adobe is 'bad'.
I finally looked around and found some alternatives to Adobe Reader; I found quite a few. I settled for 'Foxit', and it seems pretty solid (and free).
After I got it installed (and verified that it worked), I uninstalled all things Adobe (Reader, Flash, etc), and my system performance has improved significantly. I'm never going back to those bastards.