Maybe the companies should go on eBay and blacklist those selling the press kits? That would put a stop to that real quick.
It's just marketing trash. Stuff that takes up space until you throw it away.
Why would they do that? They want the press to see value in the items they send.
Also, unique collectibles from the game world aren't 'trash' in the eyes of many. I have one press kit at home, and it's for Alien Isolation, it includes a really neat USB memory stick, based on one of the toys on the table in the intro scene of the game. These collectibles are actually, quite remarkable in my opinion, because unlike the generic 'collectibles' that you get in the collectors editions of games, there aren't 2 million of them going round. They are genuine collectors items.
In general, I quite like things like that. Like, I have a CD Project Red snapback someplace too, which you can only get if you work at CD Project Red, or one of their members of staff gives it to you. Things like that hold undeniable value that's distinct from the consumer versions.
Just to add, for what it's worth, that collectors edition for Alien Isolation was sent for one of my early reviews. I didn't even think about it at the time, I was just happy to be receiving press copies for my publication. Where possible I tried to avoid receiving anything like that, but sometimes they just send them out, then what are you supposed to do. Go through the hassle of sending a huge box back to some studio in the US? For a small publication, it's just not worthwhile.