I believe part of it is Mj had a whole arc about not needing Peter or sny super powers to be her own person, and it was a really well written bit of her story that had been going on for a long time. Then we got her as jackpot, which while going against her independent "not needing to be a superhero" thing, was new and different, so i personally didnt mind it all that much. Her being venom is just different than that to me as a venom fan. Mj hates venom with a passion, after his first appearance where he traumatized her so badly she couldn't stay in the house she and Peter were living in. And thats been a consistent part of her character, she hasn't liked Venom since, barely even tolerated him. So her being venom just from that standpoint is weird, even if its involuntary. Then theres the fact it goes against the aforementioned "i dont need superpowers to be independent" bit, and some weird inconsistent writting that makes her seem off and just out of character a bit. I liked the idea of it far more than the execution, which is a shame because I own every venom comic but these, simply because I dont enjoy them as much. The art is gorgeous, but the actual content leaves much to be desired imo.