A shame you gave up after Rosa mate, think you missed out some good episodes and intriguing stories - not without faults or criticism, but enjoyable overall.
Re the viewing figures - how so a ‘nosedive’ mate? Comparing season 11’s viewing figures to season 10’s - they have improved… both seasons lose viewers as the series progresses, yet season 11’s lowest rating beats the highest rating of season 10:-
Season 11 had generally positive reviews overall in the UK mainstream media (that I read, anyway - Guardian, Mirror, Telegraph, Times, Independent & Metro).
Though I don’t know much about the complaints ‘about the PC subject matter’ - didn’t see any of it myself, yet am sure many social media clickbaiters were / are out in force (as they seemingly are so for so many other franchises / series).
Not saying the season wasn’t without it’s faults - yet hopefully some will be ironed out for Season 2 as everyone is more settled into the show. Some of the criticism over the ‘villains’ seems fair enough, as does not really delving into the companions individually (though has been an emphasis on ‘team’ this season), and a little more focus on the Doctor herself would be welcome in the future, I think.
Hope you enjoy Season 2 more mate.