Those were some really mature answers you got there. /s
The reason imo why we think its ok to treat bugs bad is because of hierarchy. We expect bugs to be beneath us and those who treat other humans bad largely come off as if others were beneath them. It is enforced through our competitive capitalist system. It gets drilled into us by playing mostly competitive games.
I think to solve this, one could ask why we rarely play cooperative games. Its always about domination and „proving yourself“. This benefits those in power because we‘re less likely to cooperate and not need their approval anymore. Its even in most movies.
Thats how we devalue bugs and other „vermin“. As someone who has lizards I touch grasshoppers (food) a lot and they are quite interesting and I cant stand if they die slowly. I‘m aware that their lives are worth something but I also aknowledge that my lizards need protein at times. I view it through the lens of potential. Humans have the potential to fly to the stars, bugs have the potential to keep our biodiversity running (=very important).