etta, in this game the d3 players are all "flawed". some are less flawed than others, i really hadnt noticed a huge gpa diff from d2 to d3... but ill take your word for it. if thats true, then its just one of the ways in d which the d3 players are flawed. your job as d3 coach is to find the least flawed players, and to find players whose limited strengths fit within your program well.
in practical terms, hs gpa is a driving factor in how many study hall minutes are needed to keep a player eligible, so it IS nice to get players with better HS gpa (which would allow you to reduce sh minutes and utilize them elsewhere). and i think higher hs gpa players are often "quick learners" who pick up team off and def more quickly (slightly)
i think most d3 coaches are happy when a recruit has hs gpa of 3.0 or better. they will usually not need too many SH minutes. and players with hs gpa of 2.5 to 3.0 are usually not held back from reaching thier potential by the need of study hall. they may need a little more initially and that may will slow their inital growth slightly, but when they get to be upperclassmen, you'll be hard pressed to tell which players had hs gpa 2.5 vs those with 3.5.
in fact, i think most coaches find plenty of occasions where recruits with hs gpa of 2.0 to 2.5 will be very desireable recruits. they may need significant study hall minutes (10-15) and that will take away from valubale skill practice. but if they have some decent strentghs coming in, they will often be worht it.
i dont want to totally dismiss the value of hs gpa, but i think most coaches look at it as only slightly more important than a tiebreaker. i dont think very many coaches have a cutoff where they wont recruit kids below a certain gpa. they may be a little reluctant with the 2.2 and under kids, but those can be gems as well.
on the other hand, many top coaches do have a set limit for Work Ethic and will not even look at players below that level. some wont take anyone below 30, or 25 or 20. hs gpa indirectly impacts player growth... WE directly impacts it. i will say that there are even some situations where low WE players can be useful (even as low as 10 or so) but you will probably need to start them right away and even then you still have to understand thier limited growth and how that compares to what you would end up with with a higher WE player.