The game is great, especially due to the mapping community making a huge effort to give you tracks / sections that never ceases to surprise / challenge you. This is a time sink, however the target audiences are mainly the professionals and newbies, if you want to play semi-casual (playing ranked & trying to get top XXX in your country) you are going to have a rough time.
The poor rating is mainly due to updates over the last few months creating a huge gap between input device performance. PC players have a significant disadvantage if you want to compete as your input is binary, either you are steering or you are not, this has a huge impact for when the vehicle starts to 'slide' resulting in unavoidable collisions at time, this applies to the new vehicles & surfaces where slightly over or under steering will result in collisions.
This where controller / steering wheel users have a massive advantage as they are able to steer much more precisely, Yes, PC does have action keys (1-5) in increments of 20%, however using it effectively introduces a HUGE element of micro managing your steering values which is a nightmare.
TL:DR - As a PC player, great game to get started, however with respect to the gaming scene, the enjoyment for semi-casual // intermediate/advanced skill PC players has been declining.