I've had mountain goat that was very, very very bad, and some that is very very good, too.
Virtually all adult male goats are going to be somewhat chewy, though. Which is not hard to understand when you cosider thier lifestyle, and compare it to the lifestyle of a veal calf, for instance.
Proper meat care is important with all animals, but when you are goat hutning there is rarely an opportuity to hang them etc. Goat hutns are rarely loaded into the truck whole, they are generlly shot in some precarious location, skinned while tied off on a shrub like tree, and the meat hacked off in chunks!
Seriously, few goats amke it down the mountain in one piece, so you are goign to have to skin and debone it o nthe mountain, and then pack it down. There is not much opportunity to cut it into quarters and hang it like a moose. There is no need to "bleed" animals that are shot in the lungs/heart with a rifle, they are already 'bled."
Once you get it down to camp/truck it's time to clean up the meat a bit. Remove any twigs/dirt/gravel/leaves etc. Pack it in a game bag, not a garbage bag.
As for cooking? Think shoudler/tough cuts. I'd use the grinder and make sioem ground goat to make spicy tacos and spghetti sauce form, and I'd be lookign at flavourful methods of moist cooking- Goat curry for example.
Best thing to do really, is before you start workign on the meat- Slice up some of the loin and pan fry it for a a bit, keep it medium. If that is tender, juicy not too strong flavoured, then the rest of your goat shoudl be pretty good. If it is tough, chewy, and gamey, ity's time to reach for the ginder, the slow cooker, and the spices.
