no.. but for a significant percentage of rail commuters there is still a tube journey involved at the city end... surely a coach from say St Albans-Golders Green or Finchley Rd would be an attractive alternative as it provides the commuter with much more chance of having a seat on the tube.. I'm sure the time penalty wouldn't be that much over the train... especially with the service being so unreliable atm that people are reportedly leaving home up to an hr earlier than they should need to and getting home just as late!
The question originally posed was 'Why hasn't there been an explosion in commuter coaches this year'. Nothing you have written has answered this question, just merely tried to demolish anybody else's reasoning for this! duncombec referred to his experience of (presumably Medway?) commuter coaches arriving at Canary Wharf and about 8 passengers on each transferring to the tube. Each of these coaches would come from a different starting point (or combination of pick up points), so in order to get a full load on one coach it would have to weave a slow and circuitous route via a number (seven?) of starting/ combination of starting points. Once a full load has been picked up, I am sure it would be direct to Golders Green or Finchley Road. However, in the morning peak, I doubt there would be many empty seats on southbound tube trains at these stations. Golders Green to City is a slow journey on the tube, with lots of intermediate stations. On the return in the evening peak these trains will be packed, and the connection with the commuter coach uncertain.
Yes, some commuters would do it, and some more during the worst of the disruption. But would an operator be prepared to take on this risk (and the work of recruiting staff, acquiring vehicles, doing the admin etc), especially suspecting that many of these commuters will go back to their regular trains when normal (ish) working is resumed, and the service likely becomes uneconomic? Coach operators are a canny lot, and will sniff out a worthwhile opportunity. The fact that not one has tried even one service perhaps gives an indication that it was felt simply not worth it. Of course they might all be fat cats, or in some conspiracy with the railway companies etc, but I doubt it.