For me, it has everything to do with lack of time. I work full time with a 2 hour commute which leaves me no time to cycle during the week. During the weekends, the kids have activities and quite frankly, i feel guilty spending time away from them since I'm not around as much during the week so weekends are primarily devoted to family. I get about an hour or two each day during the weekend but thats not enough time to go on an extended group ride (which typically lasts longer and does not work with my schedule). Therefore, I end up riding alone on the bike trail a lot. When my kids are older, I hope I could devote more time to cycling and join more group rides but unfortunately, that isn't possible now.