So far (on long distance trains) there was zero trouble buying a ticket with the conductor when he came around to check the tickets.
The famous €60-thing ("Erhöhtes Beförderungsentgelt" - respectively twice times the regular fare) effectively only existed on local trains.
will change that, is left to be seen. I don't think the staff is allowed to show too much goodwill there, since it could probably be easily exploited.
I doubt DB understands how all the big US companies made their customers their customers. It's genuinely the worn-out phrase "the customer is ALWAYS right".
You absolutely need to shoulder most of the risk involved in the service. And then the question becomes, if that's still worth it to you.
DB probably has calculated the whole thing through, realized it doesn't pay off, if the customer doesn't shoulder the risk, and thus made them shoulder it.
That ultimately makes boarding a train on impulse, in the spur of the moment, practically impossible.
The railway becomes LESS attractive, despite mobile ticketing being an extremely interesting opportunity to make railway become MORE attractive.
It's absolutely ridiculous. Especially the lack of a test-run ahead of the full implementation.