In that one survey, I think it can be taken as acceptable that Mordin and Wrex have higher ratings than Tali. For one, it's practically impossible to hate those two.
Secondly, tali's rating was brought down most likely not entirely by people who legitamitely dislike the charachter(although people like that do exist, I`m not saying that it's an impossible opinion to have), but mostly people who hate us as a group rather than the cahrachter tali herself, and just want to spite us. This isn`t an assumption, either, as it's the same story in every hate thread. maybe about 5 or 6 people actually dislike the charachter for reasons relating to her charachter and her role in the story, and the rest just because "tali fans are wierd".
Thirdly, I think even in spite of 24 people who voted 1(most likely, as said above, many just because they dislike the behavior of her fanbase), I think it is a wonderful thing that she tied Garrus for Third. In any poll, or any case, she is the most liked female charachter.
Finally, keep up the tali love, y'all!
And remember not to have discussion here get too weird, or you'll lust cause people to hate Tali because of how we act, and we don`t want that.