I think it should be noted that this generally applies to the addition of "third party apt repositories" in general, use of which is the problem that snaps fix[1]
Some snaps are built from Free Software and reproducible sources, as are some third party apt repositories.
In other words, if this criticism bothers you, then you should never install from any third party apt repositories ever. If some are acceptable to you, then so should some snaps.
If you don't want to use third party software ever, then you can still use Ubuntu without snaps.
[1] Third party apt repositories often break users' systems.