>first OP is amazing
>second OP is terrible
Why do they even bother doing this anyways.
Well, it's logical in a way.
If you have two OPs, probably produced way ahead of time, and one of them is significantly better than the other, you always want to put the better one first. Same reason why first episodes get better animation.
Because that's how they market the terrible songs that they have to work with, by piggybacking off of the success of something that's already been accepted by a large audience, in an attempt to sneak a weak single past the public by getting them to confuse a love for the show for a love for the song. The first OP is important in grabbing the crowd and generating buzz, while the second OP is not nearly as important and they can basically use whatever they want, why not take advantage of the opportunity to get rid of something that they're obligated to make popular, even though it's shit and would never become a hit otherwise.