_Turboranger
_Fiveman: a poor title, a poor song, a boring show.
Turboranger and Fiveman mainly get picked on because of how they compare to what came before. Prior to Turboranger, all of the Soda-written shows steadily got better and better. Turbo is where he begins to show definite signs of burnout and Fiveman can feel pretty phoned-in, story-wise.
Modern fans tend not to hold very negative opinions of these shows, because for the most part, modern fans haven't seen any of Soda's highly-reputed 80s shows like Liveman or Changeman. If you show Turboranger to someone who's never seen Sentai prior to Go-onger, they tend to think it's pretty badass.
_Ohranger: a show whose story was edited because of what happened in Tokyo this year, and that became annoying because of those changings.
I don't think this is a case where people actually dislike the show so much as they're frustrated by the lost potential. All of the serious parts of Ohranger have been popular pretty much for as long as I've been in the fandom, which is a long time. The comedy parts of Ohranger aren't as well-realized as what other shows at the time were doing, so they're not remembered fondly.
_Magiranger: a Harry Potter Sentai, a bad sentai because the theme of magic doesnt fit with SS.
Magiranger is not a show that anyone with good sense argues is bad. That said, a lot of long-term fans found Magiranger's hyperactive comedy style an extremely annoying turnoff when the show debuted. By comparison, more modern fans are very likely to rank it as one of their absolute favorites because they can more easily accept its style as part of Sentai.
Magiranger is
divisive because of its style, but that's not the same as accusing the show of being bad. Diehards who hate the goofy comedy these days usually fixate more on Go-onger, anyway, which took Magiranger's comedy style and either honed it to perfection or wretched excess, depending on your perspective.
_Goseiger: a SS with an empty story.
Goseiger is criticized more often for empty
characters than for anything about its story. The empty characters criticism is an entirely valid one, too, I'm not sure any of the Goseiger characters is dynamic and as static characters they're still appallingly underdeveloped. The show had an interesting concept for its Red, but the idea was clearly stymied by the weakness of his supporting cast.
Goseiger was I think meant to be a throwback to earlier days of tokusatsu, when the main cast tended to be fairly bland. Fans excused this because other characters, like the villains, would be developed into extremely memorable characters who made the heroes seem more interesting just by fighting them.
While Goseiger had some memorable villains by modern standards, though, it only had one strong enough to be worth comparing to the villains of classic Sentai (and the comparison wouldn't be entirely favorable). Goseiger's three-faction gimmick was handled such that most of its villains couldn't be developed in any sort of memorable way.
If you have boring characters fighting mostly boring villains, then you've got a show that's going to bore most people regardless of whatever else you can find to praise about it. Any comments about Goseiger's story being "empty" probably stem from that. Modern Sentai fans expect these shows to be full of over-the-top gimmicky characters and Goseiger's cast just didn't cut it.
Do you think those show deserve these opinions?
A TV show is an inanimate object. It doesn't deserve or
not deserve anything in particular. The show isn't hurt if people sit around and talk about it, either as something good or bad. Whether or not fans tend to generally like or dislike something frequently says more about the fans and why they come to the show than anything else.