The game was originally planned to be a PvE only game, but the game wasn't fun according to the data by their playtesters

There's work that is involved in properly making and balancing and creating content for a different mode. You design the entire game around how you play it, in those case PvPvE. So no, they shouldn't. And neither should devs be forced to make a game they don't want to make. If you remove the PvP from the game as-is, you will lose out on a lot of what the game is supposed to be, and the interactions and moment-to-moment gameplay you have. Not to mention you're gonna split the playerbase which is rarely healthy for a multiplayer game.

There's a reason PvP is included, and that's because it a straight up impossible to implement the sort of dynamism and unpredictability PvP adds.

There's not a lot of games like Arc Raiders, and it is the kind of game that I want. Not every game is, or should be made, for everybody. That's how you get the sort of environment of undifferentiated AAA games where they all look and play the same all designed by committee to appeal to the greatest amount of possible to earn as much as possible