It's fine for it to be gone forever, because it's been replaced by a brand new (well, 20 year old) tramway which was built since it opened and has basically rendered it awkward and unnecessary. The railway does not have to be preserved in aspic.
I challenge you to get anywhere near 600 on the existing services on the CLC in say the hour before kick-off. You won't.
Reopening it would not only be awkward, but of a direct negative impact on Castlefield and existing services. And hardly anyone used the services when they did exist, so why bother?
I'm basing it on using a pair of 323s or similar traction, which the last time I used it was packed. Usage was probably poor because before it didn't always run, some matches it would, others it wouldn't. Having an unreliable service almost guarantees poor patronage.
Who doesn't need to change? People from Liverpool, not a place well known for containing lots of MUFC fans? People from busy metropolises like Chassen Road and Humphrey Park? Seriously?
If you wanted a direct service which would serve the largest numbers of fans of this well-known South East club, a Pendolino from Euston would be it.
(I'm aware that with MCFC's recent successes and fancier stadium and MUFC's recent failures that this is not as true as it used to be)
I'm talking about once you get the train in the right direction, taking way the worry of using what for many will be an unfamiliar service, like the tram. If you know you can get the train direct from Piccadilly, or from somewhere west, it's a lot easier and less stressful than having to rely on a tram which you may never have used.
There would be nothing to stop through tickets being issued to the football ground via Metrolink, and large amounts of United-branded signage being deployed to direct passengers to the tram platforms and tell them which one to board. Some passengers probably wouldn't even notice they were on a tram rather than a train.
So does Metrolink. In fact it does it better because there are multiple stops.
Why not have both train and metrolink though? I don't know about it offering segregation when away fans will have to walk past a load of Man U fans to get to the tram stops, rather than a station which would actually be within the ground. A new station could easily be built with different entrances and exits based on who was using it and where they needed to go. Train of Man U fans arrives, they all go out exit A, which is shut when they the leave. Train of Newcastle fans arrive and they leave through exit B straight into their stand.
I think we need to get past the idea of reopening the old station in it's old form, I simply can't see THAT happening. But what I can see being useful is opening a station in a similar location using the same chord which could be more useful than the old one, and just because there's now a tram doesn't mean that the railway can automatically be done way with, that sounds like something 60 years out of date. Luckily the trams aren't CAF ones anyway....