In addition to the learning curve and the minor bugginess of Lemmy and Kbin, I feel like there may be some cognitive dissonance going on for users that are on the fence on whether they want to switch. To resolve the dissonance, one could either change their behavior (switch to Lemmy or kbin) or change their cognition (rationalize why they do not want to switch; for example by thinking that Lemmy or Kbin is too hard to use). Changing behavior can be hard especially if it is a habit built over a long period of time, so coming up with excuses for why one doesn't want to switch would be the easier thing to do.