I see this stance often - Do you mean worried for the wellbeing of the easily manipulable (e.g. children) on the platform, Or worried for the quality floor more generally?
The former has an argument, the latter does not in my opinion. Even then while I welcome a requirement for apple to notarise apps for regular install (particularly as a means to verify the source), I'd also demand the ability to run unsigned apps unrestricted - whether the barrier is self-signing, a settings checkbox, make me stare at a 30s countdown, whatever.