Call centers and customer service departments in general report statistics that are used to measure their performance. Individual employees are instructed to "resolve" tickets and to make sure that no single ticket take more than a certain amount of time to be resolved. This creates an incentive to look at the tickets in a first-in first-out order and find a way to close them. An explanation was selected from a list because that explanation has gone unchallenged when addressing similar tickets. The appointment was cancelled and the ticket was recorded as having been resolved by customer service and software. This is a win for Tesla's internal reporting on the number of tickets that require a technician to physically interact with the vehicle. They can brag about most issues being resolved by software because they're a cutting edge company and are above crude hardware fixes like those other boring car companies. If you show up in person for repairs that means, in their view, that customer service has failed.
In short, this isn't Tesla being exceptionally bad or exceptional at all. It is an example of Tesla doing the same old thing that all the other companies have been doing.
My worst car ownership experience was yelling at the people at JiffyLube for replacing filters that were in perfectly good condition and trying to charge me for it even though I only asked for an oil change (they then made a big show of shoving them back in as violently as possible). As awful as mechanics tend to be, a component being too easy to repair or replace by anyone who can read a manual is better than begging a single entity for repairs.