I think this is a situation similar to the post on the main site, about the wine guzzling guest.
IMHO, the balance of etiquette is: a host offers the guest a choice, and a guest chooses from what a host offers.
When I was little I remember my parents telling me that "Your Friend/Playdate is the guest, so they get to choose." But they were always choosing within the boundaries of what was being offered.
So if a host offers a list of drinks, a guest is rude to ask for a drink that is not on the list. It is the host's choice what to offer.
If a host and guest decide to watch television, the host is responsible for politely setting any boundaries regarding viewing choice.
There are some who seem to feel that a guest's preference trump's a host's. I feel this belief is a slippery slope that can only lead to doormattery and snowflakiness. A gracious guest should be just as determined to not be a bother as a gracious host is to cater to their guest. There is a difference between going out of your way for a guest and giving in to a guest. A guest can ask for anything, yet should expect nothing and demand even less.
The experience of having to deal with something you don't care for is a little different than not getting something you want. I feel that the OP actually endured a more negative experience as her aunt's guest - from what she described she was not given a choice when it came to television viewing and the fact that it was her least favorite channel only added insult to injury. In contrast, OP gave her aunt a choice of basically anything but the channel in question. Compare it to the aunt only offering one food item, and OP offering a full buffet that just happened to not have one food item that OP never has in the house anyway. Would it be nice if OP went out of her way to provide that one thing? Maybe, but it would be at her own discretion and not out of obligation to etiquette. The aunt was offered the metaphorical equivalent of a full buffet, and put all her attention and effort into complaining that she couldn't have the one thing she happens to want. That is rude.
I really don't understand guests who expect a host to be uncomfortable on their behalf - it is selfish. My friend hates horror movies so guess what - we don't watch horror when we have movie nights. Even if it is my choice, I wouldn't pick a movie I know she will hate - that's just sadistic.
That being said, my friend does not make a big deal about how much she hates horror movies. If I suggested a horror movie and was treated to a lecture about how awful they are as a genre and how could anyone possibly like them etc. I would feel annoyed. So I could see how aunt was maybe stung if OP said "I don't watch that channel in my house" - that may have been taken as judgement of the channel and a subsequent judgement of people who do watch it. The fact that OP suffered through the channel while visiting aunt may have complicated matters - aunt possibly assumed that OP's silence meant acceptance when it was really just silent suffering/ignoring what OP disliked.
Regardless, aunt was rude to question OP's rules about television - though OP may have let her dislike of the channel in question mar her ability to be a completely gracious host.
This is a good reminder that being a polite host not only involves providing for one's guests, but also being prepared to politely reject their requests.
Whether we're guests or hosts, we often get so caught up in saying "yes" that we forget that "no" is still allowed and should be respected.