Moffat (while a near-god in writing at times) hardly bothers with female characters. They're very... two dimensional and always end up in love with the Doctor as opposed to the complicated relationships Davies came up with.

Also the Doctor is now randomly kissing most everyone - I know Tennant did once or twice but not even close to the level Smith has been doing. Basically Moffat's been sexualising the Doctor a little bit which... doesn't sit right with everyone.

P.S: I'll probably still be watching it (and loving it) 'til they finally end the series whatever happens; just pointing out why some people have issues with it (and I sympathise with them).