I'm not sure I've ever cycled to a Calendar ride. I have no particular compunction to either. I have a life outside of cycling and I have a car to ensure cycling does not take too much of that up. Besides that, where I live, the trains pretty much to a man go into London then back out for any event I choose and thereby take an absolute age. That is if I can even get there on time, given I'm on a branch line.
Being on a train can be fab and relaxing (first class from Edinburgh to London with Greenbank last year springs to mind) but as an example, it takes anywhere from 4.5 to 5 hours to get from my local station to Shrewsbury (MC1K) with 3 changes. Then I have to cycle from Shrewsbury to my travelodge. Then to the start. TBH that's faff I can do without. Solution - bike in car, drive to hotel. 3 hours, job done. I leave when I want, I stop when I want. And it's cheaper (90% of the time).
If I lived in London or another major town, then I almost certainly would get the train to more events. As it is, not practical.
PS - Frere Yacker, if it transpires we ride the same events at any time, you are more than welcome to a lift.