Actually I think the home working issue is quite relevant to the topic.
@Peter Lanky has it right.
GM Strategy documents for a long time have called Manchester City Centre "the Regional Centre" and used a plethora of disparaging names for the Town centres surrounding it, such as "District Services Hub" (which is one phrase I saw recently in, I think it was the GM Spatial Plan). It is a political decision to treat the whole of Greater Manchester in the same way they'd treat a small town somewhere, in the way that Bath and North East Somerset Council would plan for Bath being "it" and throw the odd GP surgery and petrol station to the outlying villages. Even calling it the "Bee" network, after a symbol of the City of Manchester itself (and of no relevance to e.g. Rochdale or Altrincham) reflects that.
So bringing Metrolink to Bolton (or Wigan or Leigh or Stockport) is self-evidently a manifestation of a political plan to concentrate resources in the City Centre. Take that away, and you're left with a solution looking for a problem.
Metrolink mark 1 was, as is well known, the plan "b" (or perhaps "c" or "d") for the cancellation of the Picc-Vic tunnel. Ashton, Salford Quays and the Airport extension (to a point) allowed new corridors improved public transport links. Trafford Centre I presume is the same, but I've no idea how well used it is (or will be). Rochdale / Oldham I'm not sure what benefit is achieved that justifies the expense.
But forcing Metrolink to other areas "just because" is ludicrous in my view. Why should Metrolink go to Stockport? Who is going to use the service, and what for, given the multitude of buses and trains (some that take as little as *eight* minutes!) that already exist?
Ditto Bolton.
Double ditto Wigan / Atherton.
Every penny that would be spent on a Bolton Metrolink extension could be more usefully used providing connectivity elsewhere.