I don't see anything wrong with playpens! Open plan houses are so difficult to baby proof (and they seem to be the norm these days) so a playpen is just safer in some cases. My DD has one and I get in there with her! She loves it, it is her spot and It is just about creating a safe environment. She has had it since she started getting on the move and I just made sure it was big enough for her to crawl and roll around in.