I don't think that its about D1 vs D3 or some other level. All coaches want to win and to win you need players to work at it. I would expect that the expectation level at a D1 is higher but I know JC coaches that expect their kids to put in as much work as D1 schools.
If you want to play you need to know that it is a huge time commitment. My son is at a NAIA school and his typical schedule is wake up at 5:30am, workout from 6-7, class from 7:30 - noon, each lunch, hangout, on the field by 1:30, practice starts at 2, practice until 5, eat dinner, then study, hangout. Finally go to bed and get up tomorrow and do it again.
Its a grind but one my son wants to do more than anything and that is the key. You have to want it, if you don't then don't waste your time.