What do you consider taking care of a horse is?

I know it sounds like a kinda dumb question and im not asking because i dont know how to care for my horse. i just wanted to know what you guys consider is good care for a horse. it seems like alot of people think as long as you give it food and water then your taking care of it. for example, i have someone at my barn who has their horse locked in a stall 24/7, they never let it out, never groom it, and usually cleaning the stall is just picking manure off the top everyday and since they dont really clean it like they should, the manure builds up about a foot or so after a while and the stall stinks. the poor horse is always dirty and itchy, and always looks miserable just standing staring at a wall. everytime a horse goes by her stall she scrapes her teeth against the feeder and tries to be intimidating because shes become possesive of it from being locked up all the time. to add on to that, her legs are swollen and stiff alot because she stacks up. the owner says its arthritis, but the one time i did see her out she moves fine once she starts to move around. she is about thirty i believe, but shes been locked up for as long as i can remember, and theyve been here for years. the reason they dont want to let her out is supposedly because shes really agressive and theyre scared shell hurt someone elses horse and theyll get in trouble. but ive seen her out one time, and she was the most submissive horse out there, yielding to any horse that pushed her. quite honestly, i think theyre just lazy and dont wanna have to go get her, so they use that as an excuse. they even had a vet tell them that she needs to be let out after she got a bad abcess in her foot from standing in her own manure and urine so much, yet shes still locked up. BUT, they do come out once a day and feed her and make sure she has water in the stall(another thing, they never clean her water bucket), and pick some manure outta the stall. and if she needs a vet, theyll have a vet come out. but thats about as far as their care goes. the sad thing is, they seem to think the way they take care of her is perfectly fine. So, what do you consider good care for a horse? to me, its grooming your horse and checking them over everyday, feeding them and making sure they have clean water, cleaning their stall everyday if theyre in one, making sure if theyre in a stall that they get let out everyday for most of the day, and if theres no turnout making sure they get PLENTY of exercise out of the stall everyday.i could list alot more things but im not gonna ramble on seeing as i already have. so overall, i think taking care of a horse is keeping them physically AND mentally healthy. What about you? just a kinda random question to hear what people think.:)