"available for purchase"

so i recently few out to bakersfield, ca and back for a short work trip. here is my current rantings about this trip:
i'm not sure what has happened to the airline industry, or why some airlines can operate with a profit by NOT charging for bags and by giving certain amenities away and others have to nickel and dime you for everything. i recently flew on united airlines, which i have absolutely no status on- or in other words, i never fly on them so they don't really care about me. my flight out was from orlando to denver. i figured since it is a 3.5 hour flight that i would at least get a blanket and pillow, but no of course not. on the way back home i had a direct flight from san francisco to orlando. on this 5.5 hour flight i was CERTAIN that there must be some kind of in flight meal provided. oh boy was i wrong again. they did however have certain meal snacks "available for purchase". $6 for a cheese tray with 4 crackers. i don't understand. i mean i paid over $1000 round trip for the ticket and the airline will definitely go under if they provide a snack box for free that probably costs them $2-3 at most?! i doubt it.
i've flown on southwest which doesn't charge for bags but isn't going bankrupt, i've flown on continental where i got a free lunch on a flight from houston to orlando and they aren't going bankrupt, so why can't all airlines provide some sort of amenities or conveniences? some things i may never know...