Convince me the Bonus Action Spells rule, as written (and the general thoughts from WotC upholding it), isn't Supremely Dumb

EDIT:

Rereading Tasha's reminded me of a discussion I'd had with one of my players. The discussion itself wasn't particularly hostile, but the reprisal of it was. Strong feelings on both sides.

I am very frustrated by the inconsistency and bad explanations in the rules, and by a significant number of significant people that don't see it as unintuitive.

If you can, through some other feature, cast multiple spells with full levels, it should not matter whether those are Action or Bonus Action spells.

Anyone with more experience than this part-time, jumped almost immediately from 1st to 5th ed with a tiny stop at 3.5 along the way, Consistency-Obsessed DM?

\[Original Post, which contained a fair bit of salt\]: As title, but to give more thoughts:

I'm mostly annoyed by the interaction with Action Surge (and, probably, similar ways to Double Spell). It isn't that I think players should be able to toss around multiple levelled spells like candy, but just the very... bad execution. It is unintuitive. If a player were to, hypothetically in crazy homebrew-land, have infinite actions (presumably due to some sort of extreme version of Haste or a temporal spell), they'd still be unable to cast a single bonus action spell if they cast any other levelled spells.

It implies, on a flavor level, that there's an inherent quality Bonus Action spells have that mess with other magic, or something equally nonsensical.

Two action spells, if you can manage it, is fine, but hunter's mark and fireball is somehow a no-go even if you have two actions. Ludicrous.