Personally I can't, really. I dislike the concept of Chivalry (to me it was just an excuse for the powerful to ensure that the wars they caused would have as little effect as possible on them, not to mention extremely sexist, especially the more modern concept of it) and I'm not too fond of Saber's overly-honourable and lawful nature, either. She seems to follow rules just because they're rules, and to me that is idiotic.
I do not think she had that many options though, especially as a King back then. Such ages were different and of course the modern ages are entirely different. And she is an idealist pretty much.
I'm the opposite, honestly. A large part of why I dislike Saber so much is because of her popularity, and how she always hogs the limelight and appears everywhere. Especially when Sakura is largely ignored.
Acceptable. Very popular characters can also annoy me, especially when people care only about them. I believe part of why Sakura is the least popular out of Saber and Rin is because she is not a 'fighter' (except when she goes all yandere in HF) and because she is quite ignored in the first two routes.
What do you mean?
I thought her route focussed on her a reasonable amount, honestly. Not as much as HF does on Sakura, no, but more than UBW does on Rin. And, Saber does get some character development outside of Fate, too.
It focused a lot on her relationship with Shirou and sadly her route wasn't that exciting. Also, as a reader, you were expected to have knowledge of Arthur's legend. It would be good enough if they could add part of her background in the route.
Really?
I find the opposite. If a character is popular they tend to be disliked for that. Although, there is a certain hive-mind aspect that comes about sometimes, particularly with regards to attacking less-popular characters (Sakura on 4chan and various other places, for example).
I have noticed though that people like to put mainstream characters in their favorites, for example Lelouch, Light, etc. Perhaps that gives them some sort of image that they are fond of 'good' characters, even if majority of those characters are overrated.
That seems like a bizarre reason to like a character, honestly, but I guess that people don't have to always justify it....
It is. Or they like a x character because he/she has a lot of merchandise that they can purchase.
I think when it comes to liking a character for a design alone when they don't yet have a personality, part of it may be that the design itself kinda gives the character some personality. It may be the potential of what the design could be more than anything that draws people to it. Though then, sometimes people just like a thing because they like a thing.
I am not sure how a design would give a personality. Of course, if a designer makes a cute-looking character, most of the times you can assume that the certain character will be naive. I suppose I can give an example. But I have noticed that most of the times, a character is liked due to the design.