For what it's worth, I think that's great if it can be managed, and if not, oh well. I do not have cooks or maids or waiters, so that stuff either has to get done at the expense of outdoor time or vice versa. I feel the need to be out with them. Maybe not right at their elbow, but out where I can see and hear them. I have folded laundry, done Bible study, read books, chatted with friends, and worked our garden while they were in another part of the yard playing.
We have a wide-open fenced acre, very few toys, and only a toddler slide for play equipment. They do just fine. We have a mud patch they love (no sandbox), they play with the tee ball set, ride the bats like horses, play pretend (anything from doggies to bad guy/good guy battles). They poke at bugs and weeds and help me garden.
We manage 45 minutes on average, but I do plan to do some seat work at our picnic table when I see that they can stay focused while outside. We also have a state park nearby that I will make use of for more directed outdoor time (plant & animal study primarily).
I think it's fine to just make an effort to get them out as much as possible and not let cloudy skies hinder their play. I used to be one who thought kids couldn't play outside unless it was 75 F and sunny. Reading AO's comments on her writings snapped me out of that silliness. :D