There's certainly a big difference between nice places and nice stations. Weymouth, Exmouth, Looe and St Ives are all very nice places in my view, but the stations aren't going to win any awards.
Weymouth station in particular is thoroughly underwhelming, with its permanently closed toilets due to vandalism. A dispiriting experience is waiting in the glare of the sun on platform 1 in the early evening and seeing a 166 arrive with all the windows open, meaning it'll be a baking journey back to Bristol, whilst eastbound travellers get 444s with ultra reliable aircon sitting under the shadier platforms 2 and 3. The town however has a lovely setting with multiple places of interest IMHO.
Bournemouth station is very pleasant since its refurbishment at the turn of the century, although it's a bit of a trek to the beach. Not as bad as Poole though, since it has beaches but nothing closer than a 2.5 mile walk to the town station (Branksome is a bit closer).
Some seaside resorts served by steeply graded lines suffered from having their station plonked a long way inland above the town. Ilfracombe and Lyme Regis were two such examples. Not surprisingly, most of these lines didn't survive the 1960s.
Is any seaside town nice in February?
I stayed in St Ives in February 2019, at the start of a mini 'heatwave' when it hit 20C in southern England. With St Ives's almost Mediterranean style lighting and its sheltered harbour, it really was very pleasant.