Do you think parents should socialize toddlers as much as they can?

A friend of mine never wants to bring go to play groups because she has to drive to get there and complains about gas cost. I told her that there is a pool that has a toddler group swim time and she should bring her kid there to play with the other kids. She said she doesn't want to pay to get in plus have to drive there. Ok I understand that but the kid is never around other kids. He also doesn't talk or babble and is 22 months. Yes it might be from other things but I'm sure it would be very good for him to be around other kids and people besides his parents. He also doesn't go to daycare, neither does my son but when I can i take him to play groups. Am I wrong for being worried about this? I know hes her kid and she can do what she wants.