The main reason I ask why it's so disliked is, well... I LOVED it! It's basically just a fun and light-hearted series that serves as the perfect contrast to the dark and gritty atmosphere of Beast Machines. Not to mention that its voice cast was top-notch, consisting of several voice actors known for many cartoon and anime voice roles; all/most of whom had previously worked for Saban Entertainment and now currently work for Studiopolis.
Not to mention that it brought out one of the coolest Decepticons ever: Scourge. He was this series' answer to Starscream, but was 100 times better than any Screamer. He was cold, ruthless, militaristic, and cunning. He was neither second-in-command (Sky-Byte was) nor did he blatantly state that he wanted to take over. His schemes were long-term, appearing loyal to Megatron at first, then gradually taking matters into his own hands when the time was right. Though, he was orignally a loyal soldier, as well as a competent one, gaining much favor and praise from Megatron, which made Sky-Byte quite nervous, fearing Scourge as a threat to his rank of second to Megatron. However, towards the series' end, something happened to Scourge that makes him (and the other Decepticons) less appealing. I won't say what it is, but I'll just say that Galvatron was a jerk during this event.
Another character that was just awesome was Ultra Magnus. Forget the commanding officers of G1 and TFA Magnus, this Magnus was brutal! Hellbent on taking the Matrix from his brother, Optimus Prime, for himself, this guy made no hesitations to strike down any of his opponents, Autobot, Predacon,
or Decepticon. He cared for no one other than himself, but eventually softened up and came around to work with Optimus's team. Usually, he'd show up at the most crucial time of battle to unite with Optimus to become Omega Prime (which is still agruably the best Optimus Prime/partner combining figure). By this point, however, he was mostly now a deus ex machina used to form Omega Prime, but he still retained some coolness in his own right.
Not to mention that, aside from Animated, RiD is probably the funniest of all the TF series. While many may not go for this sort of thing, RiD is abundant with good, classic, and honest anime humor. It doesn't dominate the story, but its presence is still quite evident. Particularly in the cases of Sky-Byte (aguably one of the funniest TFs of all time), the trio of Predacons, Side Burn's obsession with little red sportscars, and other things. Basically, if you liked TFA characters such as Blitzwing and Wreck-Gar, you'll probably like the humor of RiD as well. And it did get serious later on when Fortress Maximus and Galvatron came into the story.
Overall, RiD is just a cool/fun Saturday morning cartoon series. It's best to view it with an open mind and through the eyes of a child. But hey, we're all children at heart in some way, aren't we?