Yup. Twice will do it for some. Thrice for me.
First time was the original 14-day trial that had only ONE workout to demo what was different about Xert. Second time I had already committed to TR but saw Xert reviewed by DCR so took another look. Like many, I dabbled and didn’t quite grasp how it could work without a calendar or seven zones based on FTP. Three zone strain model? Hmm… 
Up until that time I had only used canned plans and had recently moved up to what I thought would be a better canned plan approach. “PB for enthusiasts” was TR’s marketing pitch. Sweet spot was the game. I took the bait.
Third time was when TR failed me (or I failed TR?) for a second season in a row.
Time to try a different approach and commit to spending the time to learn Xert by doing it.
Not dabbling, not complaining, not arguing about the math or doubting the model. Just do it, study it, and compare the results. How does it differ? Why does it differ? Does it make a difference? Well, you know what happened with me.
I am sure D. Watson will get it now because he made the commitment. You also left this part out.
I usually use TrainerRoad and Zwift simultaneously, so this is certainly an interesting rumor. However, I just suspended my TrainerRoad account because they’ve so far been unable to incorporate unstructured outdoor rides into their Adaptive Training model. I have trouble staying on a structured workout plan because I will always choose to ride outside (preferably with friends) over sitting on the trainer.
Bingo – He wants flexibility plus option to ride Zwift. Freedom to ride! Xert does this in spades.
TR is stuck in calendar mode with %FTP blocks. 
Been there, done that. I’ve moved on. Out with the old-school, in with a new paradigm shift.
Not ready to do that? Fine. Like I said, many are not candidates for Xert.
Does that make Xert is a niche player? Sure, but those who are content riding a daily dose of blue blocks and being told what to do aren’t ready to learn how to self-coach or don’t want to.
Now you could argue Xert should try to cater to that group in order to gain market share but that runs contrary to the current focus. 