Very.

Quite the opposite, the's very unpopular. I'd say that either her or Elsa are the most hated Disney Princess on Fanpop.

What I've noticed is that she's very popular with some, and very unpopular with others. Most people love or hate her. Honestly I'm one of the very few people who doesn't feel strongly either way.

I'm not sure. There are a handful of people who have very strong negative opinions about Ariel, which is why many think she's unpopular. Some of her non-fans will incessantly point out her "unforgivable" flaws.
On the other hand, she has a good amount of dedicated fans who will defend her to death. Then there is that small group of popele who are neutral about her, or simply like her, including me.

A few people hate or strongly criticize her but her diehard fans outnumber her detractors IMO.

Most definitely.

People are only choosing Yes because they hate/dislike her.

She's in first place for a lot of polls.

Very much. She have a lot of fanatic fans here.

Absolutely. She wins, or comes close to winning, a fair amount of positive polls (best voice, prettiest, etc.) and seems to have more... uh, passionate?... fans in this club than any other DP.