Well the reason they have no useful function in PVE is because they are not working properly like in potco. The original game's developers had this mechanic in the game from the beginning to make it so players could "tag" enemies while they are invincible so if another player were to insta-kill it, they would still get XP for attacking it. The bubble is still there and the enemy is still invulnerable for that very short amount of time, but the player can attack it to get XP and loot. The same goes for a large group at a boss. There wouldn't be anyone missing loot from it dying too quickly if they fixed spawn bubbles. The whole idea and mechanic of "tagging" an enemy in the spawn bubble dates back before loot was even implemented into the game with the El Patron's Lost Weapons update back in 2010.
This gives no advantage to anyone nor does it make anything easier. I don't know why you are so against it. You keep mentioning bubbles being useless and suggesting that they should be removed. If you are solely against this idea because of the fact that you think spawn bubbles should be removed entirely rather than changed to how they were, I don't know how to respond to that. I don't think the devs would ever remove spawn bubbles. Ever.
Nonetheless you should probably start your own thread suggesting that rather than continuously mentioning on this thread.