All you have to do is look at the fact that PG has been consistently effusive about Sam in his public comments and essays since the mid 00s through till the present day, for it to be clear that Sam wasn’t simply fired.
Of course these situations are always complex behind the scenes, with many factors and considerations at play.
But the no he must really just have been fired against his will claim just doesn’t pass the sniff test to anyone paying attention.
I wonder how much of the impulse to believe (in the face of the evidence) that Altman parted ways with YC/PG on bad terms is really rooted in an impulse to believe that YC/PG couldn't be complicit in enabling the kind of person that it now increasingly appears that Altman is.
If Altman truly is as bad a person as it appears that he might be, that doesn't reflect well on the people who have praised him through the last few decades. If you like those people, then cognitive dissonance forces you to either believe that Altman is being unduly villainized or to believe that the people that you like secretly hate him but just can't say so openly.
Of course these situations are always complex behind the scenes, with many factors and considerations at play.
But the no he must really just have been fired against his will claim just doesn’t pass the sniff test to anyone paying attention.