>>43342292It's not even subtext it's text within the show itself
Charizard thought it was hot shit and didn't respect Ash anymore since it thought it was such a great and powerful monster it didn't give a shit about being commanded anymore. It only fought when it felt like it was faced with an opponent it personally wanted to best, it wasn't going to fight for Ash's sake because it didn't care about Ash anymore.
This is literally what they say in every episode where it does this.
Eventually Ash earns Charizard's respect obviously