I think they only used Lotso since he was a main character of the newest movie. This may one of the few times a character with evil tendancies due to abadoment issues is not fully redeemed. I guess Stinky Pete wasn't redeemed either.
Lotso wasn't mean to the kids, just everyone else.
Some have said it I think. Since he is a made up toy, there are no licensing or copyrights to obtain. Easy way to promote and collect on that marketing.
I found my son's Buzz. He was in the guest room with Flik and Tigger.

I have placed back on a shelf in his room. Waiting to see when he noticied him and what he does.
His room is full of little creatures, dragons, dinos and transforming types ready for battle. He says they are protecting his room.

He ditched Buzz but kept Skippy from Alien Encounter ( Before Stitch). DS hates stitch because he ruined this ride.