I absolutely agree with you. The level of ticket acceptance that has been arranged is wholly inadequate. Expecting passengers to travel via Sheffield, take road transport to Doncaster or wait in excess of an hour for a (presumably cheaper) VTEC service when other, more suitable services call, is to many travellers, unnaceptable.
For leisure passengers with 'loose' travel plans, catching "any Hull trains service" may be fine, but for those on tighter schedules, high spending business passengers for example, the alternative arrangements simply aren't up to the expected standards of rail travel.
On the one hand, it could be argued that the lack of ticket acceptance highlights the problems of a fragmented, privatised system. However my personal take is that Hull Trains, or more likely their parent First group, have tried to control costs via limited ticket acceptance at the expense of customer convience. I think it's going to cost them a lot more in terms of customer loyalty in the medium to long term. That's a real shame.