Okay, I misunderstood the earlier post, I misread it as being about flights from other countries to Dresden and/or Hamburg.
But there will still be some numbers of passengers arriving at Dresden from other countries, via a change of plane at (e.g.) Frankfurt or Munich, who won't necessarily be familiar with German ticketing methods.
As it happens, I do agree that these can be inconsistent and potentially confusing. On my last trip to (I think) Munich, I bought an S-bahn ticket from the airport station TVM, but it wouldn't fit the platform validator. Fortunately a local was there to tell me that that particular type of ticket was sold pre-validated and didn't need to be (in fact couldn't be) stamped.