BRI, I think the limit is actually 200 gallons. Either way, it's an absurd amount that you would never be able to brew and drink in a year. Well, hopefully.
And a significant part of the reason that it's illegal to distill your own hard alcohol is for safety reasons...any time you're selling illegal liquor, anything could be in that sh#t. Look at how many people died during prohibition from drinking moonshine. Not to mention that you're dealing with generally large open flames burning for a long period of time, big pieces of equipment, and other safety concerns that you really don't have with homebrewing. But obviously the #1 reason is the tax $$$.