Copy and paste of what he said -
It was a mutual decision. We grew concerned that we were already making a movie that veered away from fan expectations, and when we showed it to some small, select audiences, our concerns were validated... so we removed the Emissaries AND the hybrids in favor of a traditional "hunt" finale, which -- in my opinion -- squandered the notion that the Predators have a larger, unseen civilization and other concerns besides sports hunting -- like, for instance, saving their civilization from extinction. It was decided that this, plus the humor in the film, was too much for the Predator fan base to swallow... and sadly, the box office and critical reception proved we were right. We should have made a cheaper, more predictable movie, and not tried to do something new.
But what do I know? I was just the co-writer.
So the problem was not the quality in scripting, casting, direction and execution, it was that they tried something new and the fans (and critics?) wanted predictable.
Doing something new was fine.
Doing what they specifically did, less so...
It's the fine line (not that subtle though) between adding to a franchise and just kicking it in the nuts by doing the complete opposite of what fans love.
In a way, The Last Jedi toyed with people's expectations too, but it managed to keep it all in character (if you're willing to accept it not living up to your personal fanboy dreams) rather than just make it about something completely different.
The Predator is a nice film, just a very poorly thought through sequel. Whoever pushed this through Fox should ask themselves if they get what the franchise is about.