Why will the US Army accept me without a HS DIPLOMA yet the US Navy wont?

It doesn't matter if you score a 99 on the ASVAB, if the Navy isn't accepting GEDs right now you aren't going to get in. It has nothing to do with the recruiter thinking you aren't worth their time; you could go across town and they will still give you the same answer. The reason why you can join the Army but not the Navy is because the Army made a decision a few months ago to give GED holders who don't require moral waivers a chance to serve without forcing them to get 15 semester hours of college. Considering the way the economy is, you should be glad you have that opportunity. You should take advantage of it while you still can because they can stop taking GEDs at anytime and then you will have no choice but to get 15 semester hours no matter what branch you go to while still being unemployed and possibly living on the street if your mom kicks you out. The Army has a lot of different jobs to offer, you may find one close to what you would like to do in the Navy assuming you're not trying to work on a sub or anything like that.