It does indeed seem like a very poor reason, to me. I believe the other reasons given, i.e. that they'd like all of their resources to be equal and that it was unfair to those generating e-mail tickets, are more valid. If there is a rampant issue with staff becoming too big-headed over their positions, then I suppose this makes a bit more sense in that context.

However! Saying that staff should not be recognized is a counter-productive to the Graal staff model of 'hiring' unpaid people to do hard work for little to no recognition. If answering questions all day in a level-headed manner has the unfortunate side-effect of creating celebrities out of the more visible staff while the invisible staff have no clout, why not just mention all of the unseen people as well? So long as your staff members are not acting out of their expected behavior, I know I would much rather have my volunteers feel like they are a welcome addition rather than a nothing person dedicated to penniless work without note.

The interesting issue here is that the entirety of what was said above does not, in any way, address the issue that the sign was much simpler (or perhaps more familiar) than the e-mail ticket solution. Apples and oranges, really. If nothing else, you've got to make it very clear how you've transitioned away so as to not cause any confusion to people. That this thread exists is a good sign that people will make up their own reasons, often negative, to the benefit of no one.