Yes!
This! Absolutely, precisely this.
Writing off these criticisms with a mere "if you don't trust why do you even bother" is a refusal to respond to real, valid, reasoned criticism.
Being unsure of motive is certainly part of it. I am, very frequently, playing with GMs I've never played with before, so it is important to clearly establish trust, which means NOT doing tons of things in secret and writing it off with "don't you trust me?" But by far the bigger components are with knowledge, judgment, self-awareness, and reasoning capacity.
Because I find a great many GMs are quite acceptable in terms of their intent. I just see a lot--and I mean a LOT--of evidence that most GMs are spotty at best on translating that intent into reality, specifically because of a breakdown of knowledge, judgment, self-awareness, or reasoning. See: the iterative probability problem, aka "roll Stealth every single round to continue hiding." Statistical reasoning is hard. It is not some horrible moral failing for someone to have faulty reasoning ability when it comes to something like this. In fact, that is the default state of being for humans.
There is, I agree, a pretty serious error on the player's part if they choose to play with a GM whose motives they distrust.
There is no error on the player's part for choosing to play with a GM whose knowledge, judgment, self-awareness, or reasoning capacity they sometimes distrust. Because that statement--"sometimes I don't completely trust the knowledge, judgment, self-awareness, or reasoning capacity of X"--is true of literally all human beings on this Earth.
I don't even trust MY OWN knowledge, judgment, self-awareness, or reasoning capacity sometimes!