or c) they are eminently sensible?
I am guessing you haven't lived anywhere else and only visited other cities so I won't argue all points as you seem to be wrong with everything you say from my experiences & point of view
But: no the beach is not dirty, well, aye, kinda but it's still one of the cleanest in the UK

It also has better fucking sand than most and head north of the Don and it only gets better...
There is nothing for young people to do anywhere. This is a fact that is true of the entire world - it's what being a teenager involves, but yes I imagine it sucks.
Aberdeen's nightclubs & bars sub-standard?! fuxake. Aberdeen has some of the best nightlife you will find in the UK. It loses big time on attracting big name bands & djs, aye, but the venues are top class.
But see all that, none of it matters, all it means is that you don't like the place and I do. If all you want is a Big (identikit) European City then Aberdeen isn't for you, if you want a parochial small town then Aberdeen isn't for you.
If you want a bit more variety and interest than either provide then you won't do better in Scotland than Aberdeen, and you'd be hard pushed to find a better place to live within the UK.