I can understand that it feels frustrating at times, but this kind of mechanics are entirely part of RPG's and board games.
Also, it works the same for everyone.
By giving an extra potential twist to the batlles, it helps keeping things fresh when you play against the same enemy/composition often.
Then, the chances it turn the sides of a batlle are actually limited. It just feels bad when you get one hence the reaction. And it's also more visible and impactful right now because companies are not that big just yet.
I remember having this talk over and over when I was doing some competitive PVP in WoW (even if in my opinion e-sports in MMO's is a bad idea) and for long I shared your pov. But when you think to it, especially in a game where stuff can't affect your critical rate, it's a pretty balanced mechanic. It brings some extra excitement to the table !
Of course that's my pov, feel free to discuss it