@The_Jerol To make it extremely simple, you can say that there is no such thing as a truly random number. There are just series of numbers generated according to patterns which mimic randomly occurring numbers. When you enter a battle you get a "seed", basically a spot on the series of numbers. This spot is determined in such a way so as to appear random to the casual gamer.
So you are right when you say that there is no randomness. But you are extrapolating your conclusions from this. Just because it isn't "random" in a very broad sense of the term, doesn't mean that developers have a secret agenda to screw you over. This conclusion does not follow from the premises given.
You also need to take into account the widely observed phenomenon of confirmation bias. Nobody is immune to this. Me neither. Simply put, we tend to attribute our own successes to skill, and others (AI) successes to luck.
This is why a mere feeling of "it has to be rigged, look at how many crits they get" cannot and should not hold any weight in a discussion aiming at more than superficial banter. We need cold, hard numbers. And if you are unwilling to produce numbers that support your thesis, do not expect others to just give you the benefit of a doubt.