I have owned Acrobat 9 for 5-6 years and have used it for .pdf document manipulation at least several times a month.  Of course, Acrobat Reader DC has been around for a while now, too, and has a function that I use almost daily - Fill & Sign.  These two applications, with different features & uses, co-existed on my rigs quite happily until about 3 weeks ago.

Upon launching Reader DC one day, I was greeted with a message that my version had been automatically 'upgraded' to the 64-bit version.  Cool!  What's not to like, right?  Doubtless some language buried in the software agreement for Adobe Updater granted my permission to do this but it happened unprompted with no option to decline and no further information about the 'upgrade' was provided or linked.

Several days later when I needed to use Acrobat 9, the context-menu link to open a .pdf with Acrobat 9 was missing.  Seemed odd.  When I went looking for Acrobat 9 I discovered that it had been silently uninstalled.  Poof.  Gone.  Paid for, but gone.

I pulled out my install disc and attempted to re-install it and was greeted with this lovely missive:

"A more functional Adobe product is already installed on your computer.  Installation will be terminated."

Well.  The main functions I used Acrobat 9 for were adding, deleting and rotating pages in multipage .pdf's.  Given the above, you will not be shocked to learn that no such functions are present in the free version of Acrobat Reader DC - not exactly 'more functional' IMHO.  Gaining access to those functions in Reader DC will only cost a minimum of $10 a month.  Such a deal.

Whether technically legal or not, uninstalling a paid-for product without explicit permission is flat out unethical.  I can't imagine a more 'Fuck you, customer' thing than this.

As they say about the CCP, Adobe is asshole.

End of rant.  FWIW.