And why shouldn't you
It's your own opinion and it should be! I personally disliked her last season but liked her in this season. What I didn't like is how the Doctor went against his own rules and shot a man, forcing them to regenerate and was willing to blow up the Universe because of Clara. it's so not him. But on the other hand Ten went far to see and talk to Rose one more time at the end of season 2. I just wish they would stop leaving open ends for a possible return.
At the first runthrough I wasn't too keen on the season finale, because I felt it ruined Clara's sacrifice, then I watched it again with my flatmate and I actually ended up appreciating it much more - though I still dislike the ending, because while Clara will have to go back, she can also seemingly put off her death indefinitely, which just makes the whole thing a bit pointless.
Right before i go into my own rantful opinion ^^ i wanna correct you Nessy, He wasn't willing to plow up the universe, the fact he literally spent 4 billion years in grief for Clara sent him waaay off the rails, of course he's gonna shoot the guy who killed his friend and imprisoned him for 4 billion years, it was the fact that Clara died which turned the Doctor into such a stubborn git, I do agree with ME/Ashildr's statement on the Hybrid it is a combo of the Doctor and Clara, his love for her allowed him to end Gallifreyian life he stood in the ruins of his people with two other people and i think that it's actually a combination of all three, Me allowed Rigsy to become the bait and she sided with the Quantum Shade, she was a literal accomplice in Clara's death.
Right now onto my actual thoughts on the finale, I loathe Clara during that crap with Pink, boo hoo he died but we literally see her pull a U-turnin this season (anyone else like Bonny the Zygon better than normal Clara) I don't like the fact that Clara keeps getting open endings, she died, she in fact performed a sacrifice which, if you are unlike me, left you teary, she died for a friend, that's the best than most of his recent companions. I didn't care for the Mind Wiping aspect, i thought the Doctor had a large resistance to all mental buggery like that, but nope that got retconned.
I loved Heaven Sent and i do think Capaldi was brilliant on his own in that one ^^, just damn i can't say anything negative because how often do we actually see JUST the main actor and the villain and the villain is silent? I loved the fact that we finally see what would cause the Doctor to lay aside his rules, the death of a close is not the closest friend. Clara Learnt is real name, stepped into his time stream and hell even helped to altar his personal history, what the hell did Amy and Rory do? One Died and the other would date themself in a heartbeat. I don't know about anyone else but i personally loved The Doctor finally getting his form of vengeance on those who caused the Time War and also The Doctor's Regeneration from 10th to 11th.
Hmm what else... ah yes as
@Terminus says, you can't leave Gallifrey 2nd, christ the Doctor has been searching for his home for a Loooong time, ever since the day he realised he didn't kill them all in fact and then to just have them shunt it aside was quite frankly insulting, they went to a hell of a lot of effort to make the Citadel look freaking awesome and then nope we don't care it can go to hell. They literally built up Gallifrey from the 10th onwards more specifically "Gridlock"/"The Sound of Drums" making us want to see what they could do with Gallifrey we got a teaser of a destroyed Capitol in Day of the Doctor and then in Hell Bent we actually see Gallifrey as a whole and they just shunt it to the side. Kinda saddens me that they'd do that, Though i think they've left Galifrey's fate kinda Ambiguous, we know it's destroyed by Clara and The Doctor but it was also hidden at the end of time bar a system or two so i do think they have an opportunity to either bring in a brand new Dalek War, renewing the Time War (which is what i think) or destroy some other way or maybe even bring it back fully.