Don't like Predators? Don't play with them. But why deliberately exclude Preds from everyone because you dislike them? RPGs are all about player choice.
Predator is a separate intellectual property. It would almost certainly require a separate license, and makes more sense as a separate but compatible core should they ever decide to add it.
It would be like excluding Jar Jar Binks (I can't stand him) from Star Wars FFG. Some players might like Gungans, so let them have Gungans in their game. I wouldn't complain about it though because it doesn't affect me and my games. And I certainly wouldn't go out of my way to actively lobby to exclude Gungans.
No, it's not anywhere near that. Jar Jar is part of the Star Wars license, lock, stock, and barrel.
Predator is not part of the Alien IP. It would require a license of its own. Alien is Ridley Scott; Predator is Jim Thomas and John Thomas (the Thomas Brothers).
Any time Fox licenses something out, they pay a royalty to the creators, and include that amount as part off the license fee. Fox does business as a US corporation, and defaults to US IP law. Which means that, most of the time, they pay royalties to IP creators for IP they control. The royalties are fixed in the initial contract.
When you mix two IP's, you still pay the full royalty to both creators. As a derivative of both IPs, under US law, it's a third IP which requires license from both source IP's. Which means fox has to pay Mr Scott his full fee for an Alien product, and the Thomas Brothers their full fee.
AVP is thus almost certainly double cost to Fox. They WILL pass it on.
Likewise, there have been other Predator and Aliens crossovers. Judge Dredd has had cross-over comics for both. Don't expect the owners to allow a competing JD line when they just recently licensed a Judge Dredd RPG..