Would be interesting to know why these people voted it the worst. Perhaps they fell foul of their well known rules and had to pay up?
Personally I've used them several times a year since 2001, well over 70 flights now and never had a single issue, not even a delay (other than once I got caught up in a bomb scare at Kaunas airport which I can hardly blame FR for). It's funny, I have a friend who pays attention to every negative FR story out there, claiming they are a disgrace and he will avoid them. He's flown with them 3 times. Every time he arrived at his destination early, the flights were the cheapest by far, had good times and he even sat with his travel partner without paying for seats either. He's had nothing but good experiences but just likes to jump on bandwagons, as do a lot of FR detractors. Whatever they are doing they need to keep doing it. Surveys like this don't reflect on the fact that they are one of the most successful airlines in the world.
And no, I'm not an FR employee, I have absolutely nothing to do with them, just a very satisfied customer.