It’s like the Upstart and Systemd upgrades to the Linux init system. Boy, did that get some people upset. This time around its Snap, Flatpack, and other efforts to solve application compatibility and security issues. (see 2daygeek).
The thing is, software applications often depend upon common libraries of functions. Some of these libraries are provided by the system, some are provided by development environments and some by library builders. These function libraries change as bugs are fixed, security holes plugged, and enhancements made. The fixes and changes can sometimes surprise applications that use the library to misbehave. Different expectations about the system and functions available can create conflicts that make support and operation of the software difficult.
Another problem is that some applications get into system areas where they can do damage. This can be intentional, like in malware, or unintentional due to error or oversight. The term sandbox was applied to techniques to limit this sort of problem. CPU designers have been adding sandbox capabilities at the lowest levels in terms of memory protections and user privilege levels and thread isolation. Systems have picked up on these new CPU capabilities and provided such things as containers and virtual machines and other security mechanisms (see nixCraft).
Like Ubuntu coming up with Upstart and then folding over to Systemd as that became accepted as a solution to startup dependencies and other issues, Ubuntu developed Snaps to solve application issues. Fedora is putting its efforts behind Flatpack. And the bigots and trolls are out in force, again, throwing brickbats. There seems to be a larger ‘hate Shuttleworth and Ubuntu’ contingent in this mob but that may be due to the target being easier to personify and identify. Whatever. The brickbat quotient tells you it is an important issue and effective solutions are starting to appear.