Your stats are fine imo, in the sense that they're in a range that can be played profitably at 20NL. It's all about postflop play and utilizing implied odds. If you look at players who beat these microstakes you'll see they (open) limp a lot. If the table is loose passive (ie a lot of them call raises but they don't raise often) then I think if you raise a lot of hands (like 22 and 75s) you're actually shooting yourself in the foot.

When you get to stakes where there's a lot of preflop raising and 3betting, a lot of pots are HU and postflop a lot of pressure is applied, then I think it's more crucial to gun for the 25/20 (or whatever) ideal.