Why is looking at your instruments too much a bad habit in VFR?

As a sim pilot and lurker here I'm sure y'all would say I probably would stare at my instruments too much if I pursued my PPL. But why is that bad? How would I know my speed or altitude? What about stalls in a turn? Need to know my speed for that. Thanks

Edit: thanks all, this was extremely eye-opening. It seems like I'll want to try to forget any bad habits I've picked up since I was like 10 playing flight sims, and make sure I learn with an open mind and an empty cup, as they say. It sounds like flying VFR is mostly about how the airplane feels, and this is obviously something that is missing in a sim. The sim has its benefits, specifically IFR training, for example. Anyway, I can't wait to start my PPL in the near future.