A cable car would be much cheaper and easier, and you could include it in the price of rail tickets and therefore journey planners.
I still think it would be a waste of time though, I’m struggling to think what groups would really benefit. A 500m walk isn’t seen as a problem in Glasgow, Birmingham, London or many other cities.
I'm stuggling to agree with the bit about a 500m walk. It's a problem for the many folk trying to get through Glasgow!
Much has been said against the walk between Euston and St Pancras; the walk between Queen Street and Glasgow Central; and here the walk across Bradford; and for how long has Manchester schemed to connect its Victoria with Piccadilly?!
Please could we step back from the cynicism and look at what goes on elsewhere? Why have Germany and Austria spent a fortune on new, through main stations? Why do cities have cross-rails (Cross-Rails over the four points of the compass in London; a Cross City Line in Birmingham)? Even Inverness has got one, albeit with reversal.
The hypothetical and speculative business case for connecting the two sides of Bradford would be based on an assessment of the likely traffic flows if, for example the Skipton - Keighley - Bradford services could continue to Leeds via Pudsey or alternatively to Wakefield. And the Ilkley - Bradfords proceeding to Halifax and Huddersfield or Manchester (yes, with future electrification). And on an inter-city operator giving Bradford a long-distance, through service of some sort. And as the years go by, the populations on either side of the Bradford gap will tend to grow.
I don't expect any progress on the Bradford front in my lifetime because the business case probably isn't there. But the Welwyn viaducts, Castlefield quadruplings, Glasgow crossings and Bradford Gap will never go away until a favourable economic or political wind blows here or there and urges that any of these particular problems be fixed.