What are Theseus’ expectations about the Craftsmen’s play? Why are those expectations in some measure ironic?

When Philostrate gives Theseus the summaries of the choices of plays, Theseus reads that the play the craftsmen plan to perform is both "tedious" and "brief" as well as both "tragical" and "merry".  The opposites intrigue Theseus and asks Philostrate who the actors are.  Upon learning that they are craftsmen from the area he says this is the play he wants to see because he says that something won't be bad when it's done by simple people who give it much effort.  When Hippolyta says she doesn't want to make fun of people and laugh at them at their expense, Theseus says that's not the case at all.  He tells her that they are actually honoring these craftsmen by letting them perform.  The craftsmen, he says, are simple people, and by giving them this chance to perform, even if the performance is bad, is a good deed because it is acknowledging that the people at least tried to do their best. Theseus is probably just saying this to get on Hippolyta's good side and he does not really want to see a bad play just to make some common people feel good.  Still, he does not expect the play to be good by any means.  Naturally, the play is not good and when Theseus dismisses the players and tells them they don't need an epilogue, he calls the play "palpable-gross" meaning that it was an obviously bad play.  His expectations were for a bad play and that's what was delivered.