Bombarding Our Children's Playtime

I sometimes feel that because our children have lost the advantage of playing outside in the neighbourhood like we used to, we got so occupied with filling their time with activities that at some times, may be too much. I was sitting with two other mamas today who's sons go to preschool with my son, so they are all about 3 years old. We were discussing placing our boys in two activities after school which would mean that they would have sports everyday after school, all week long. We were all very excited, but then I started to think, are we overdoing it? While the activities are only one hour a day, are we still overdoing it by teaching them that they have to go out and do something to have fun? But when I think of it, I have about 7 hours a day after preschool to entertain him, after the building blocks, the finger painting, the play dough, the TV and the other miscellaneous activities we do together, I still have about three hours of time to waste. I see it with the other older kids in the family too, two activities per child per week. But what's the alternative? Even if I did want Yousef to go outside and play, the streets aren't safe, the people aren't safe and there are no other kids!