For several years now, Ubuntu/Canonical has been making decisions in what many consider to be an arbitrary & dictatorial manner that is seen as contradictory to the philosophy and ideals of  FOSS and Linux.

Many "old timers" felt that Canonical ran over users roughshod when they shifted from Gnome2 to Gnome3. This was the beginning of the split and resulted in several new distros and DE's, such as Mate, etc.

Recently, Ubuntu/Canonical have embraced "Snaps", which some feel are inconsistent with many FOSS & Linux values. Some criticisms include:

* snaps come bundled with dependencies, so they're larger than their counterparts from other package managers.
* snaps are slower to run than traditional packages.
* snap distribution requires devs to set up an account with Canonical and host their snaps on it. 
* snap packages don't go through stringent checks and reviews by the community.
* Snap's back-end is closed-source and controlled by Canonical.

So, this is seen as yet another instance of Ubuntu/Canonical ramming things down the Linux community's throat. Many people see Canonical as acting like Microsoft and they've simply had enough of it. 

 Thanks for the explanation!