Eh, well, Paddington is one I had in mind when I posted
I consider the dirt on the glass of great big overall roofs to serve a valuable function. A giant glass shed is, as we all know, a greenhouse, and having one end wall missing doesn't make a fat lot of difference to conditions at the other end in a thing that size. On sunny days, a station like that can get horribly stuffy and stifling inside, and Paddington could get pretty awful even in the 70s. Cleaning the roof makes that problem worse, and it gets worse still when at the same time they remove some of the shading panels placed there by builders who understood this point and replace them with more glass.
Concourses too have got a lot less pleasant with the sprouting of garishly-lit sense-battering cluttery room-sized cubes all trying to flog you a different kind of crap, all out in the open and getting in the way, and often emitting greasy fumes which make the abovementioned sunny-day stuffiness that much worse. Time was when you simply had
a buffet, decently placed in an actual room in the station structure, designated with a simple black and white Rail Alphabet sign, and selling a range of food from which it was actually possible to select some satisfying quantity of belly ballast without wondering where all your money had gone and why you were still hungry; and if you weren't hungry in the first place, it would simply leave you alone instead of getting in your face and screaming at you to try and persuade you otherwise.
As an ideal I would hold up St Pancras in the Peak era changed ONLY by removal of the grime and in
no other way: the muckiness and rubbish on the tracks etc was the only thing wrong with it. It had the facilities to perform those functions which are a necessary part of making a train journey and for the rest it was spacious and
peaceful. All you had to tune out was the engine noise and that's pretty automatic anyway. Stations these days are
not peaceful because they encourage the invasion of random graspers all trying to force themselves on your attention, so the amount of crap clogging the mental filters goes through the roof (and a great deal of research and design effort has been put into the crap precisely in order to achieve that result). It's called
sensory overload; it's an inherent problem in a large busy station anyway, and encouraging deliberate actions to make it worse does not do a station any favours.
...and it very quickly used to go all loose and baggy like a pair of wrinkly underpants, which was - entirely irrationally - distinctly discouraging even though it didn't make any difference to what it was like to sit on.