Of the open access operators, WMSR was the last to get started, launching it's services just before the recession took hold. I expect that the original business plan would have made more sense had the recession not happened, nor been so deep. I recall threads on here & other forums around the time of WMSR's launch that inferred that the original 5 trains each way on weekdays seemed somewhat ambitious which has been borne out by experience.!
Whilst there isn't a huge market from the Wrexham end, Shrewsbury & Telford should both generate sufficient passenger numbers for a few trains to/from London each day. The former as a railhead for a large part of Shropshire & mid Wales & the latter due to the number of business located there.
As I see it, the main problem for WMSR is the journey time. The majority of customers travelling on business between Telford & London (who are the ones that pay the premium fares) will consider journey time over comfort almost every time. They just want to get from A-B as quickly as possible, often want to work whilt on the move & aren't too fussed about having a full meal en-route. Using that logic, most business types will elect to use Virgin, either by a change at Wolves or fast car to the nearest Virgin train service.
There is also a market for leisure travellers who dislike changing trains and WMSR provides a good service for this market, who generally are not so concerned about journey times. However, this market is never going to pay the way for the company as these cusomers generally travel off peak, often on railcard discounted or advance purchase tickets.
I've used WMSR a few times & have always been impressed by the excellent service. As other posters have said though, this on it's own is not enough to balance the books. It's also expensive to operate with 67's & MK3's and as nice as the refurbished MK3's are, those costs still have to be met fully through the farebox as WMSR is not a franchised operator. The on board service also has to be paid for, as well as the staff wages.
In my opinion, additional calls in the West Midlands are something of a red herring. For the few trains WMSR run each day,(even when it was 5 each way on weekdays), the West Coast franchise is hardly going to be troubled by this. Personally, I would concentrate on Tame Bridge as a railhead for the West Midlands & continue to reduce journey times as much as possible. It's a pity that a chord could not be built so that WMSR services could access Snow Hill from the north & that way, a few of the pathing issues in the West Midlands may be avoided.
Personally, I would only run one or two trains each day from the Wrexham end (mainly for servicing and leisure market) & would concentrate resources between Shrewsbury and London. With reduced journey times, it should be possible to build up a decent niche market from Shropshire to London.
Given a faster journey time, WMSR should do well between Shropshire & London & I do wish it every success for the future. However, unless revenues rise & costs are controlled, the future doesn't bode well based on present circumstances.