Percy Jackson is freaking terrifying
I bet, after hearing about Tartarus (the gods were all pretty much incapacitated when it happened), the gods decided they should just leave Percy alone.
Because like, before all of that, I think the gods were a little intimidated of Percy (especially after he gave up immortality), and of course Hera would have to avoid Percy and Annabeth for the rest of their existence because they would not hold back from her. So, like, after Tartarus, Percy has seen everything. He's faced Tartarus himself, he's not threatened by the gods.
This is proven in ToA when Apollo shows up at his door and Percy's just like, "Why?" No respect or acknowledgment of Apollo being a literal God (he didn't know that Apollo had been turned human at this point). Apollo was even a little nervous around him (and Meg freaking hid behind Apollo).
The gods felt threatened by Percy already, but after Tartarus, I bet NONE of them wanted to go near him again.