My son went to a play based preschool/daycare. (I worked at the time.) There was NEVER any homework for any of the kids and very little emphasis was made on formal school work. Kids were never sat down to fill out worksheets, although they spend plenty of time drawing, coloring, using scissors. And those 6 months away from K, a few more skills we worked on to make sure they were K ready. I was very happy with what my son did there, he had a lot of choice of activity, there were other kids and lots of time to run around outside. My son could read at 3, and we primarily worked on this at home. At school they knew he could read, so they encouraged him to take books off the shelf to read to himself. All kids were encouraged to do this even if they were only looking at the pictures. The key to this place was the teachers. They are wonderful and have worked with the preschool kids for over 20 years.
To the original poster. Trust your instinct, if this is not going well it's probably not the right environment for your son. There are probably other options to help him get peers involvement. Or other preschools. Sometimes what looks the best to us from the outside doesn't end up being the right solution for our own children. Good Luck.
