Leaving aside the question of whether Rashid needs the experience or not (he’ll still get some, with the Performance Squad touring too), the choice should have been based on which spinners were more likely to take wickets.
Panesar, despite some poor form recently, was always a near-certainty to be selected, so it came down to a three-way decision between Swann, Rashid and Samit Patel. Of those three, Rashid has had the better season for his county, but Swann has more international experience.
Amongst the reasons given for Swann’s inclusion is the fact that he’s right-handed. That’s just silly. Also, his batting has been touted as a reason for his selection, but he’s probably a worse batsman than Rashid.
The England selectors should probably be given the benefit of the doubt, but I reserve the right to say ‘I told you so’ at a later date.