We're not talking about cashiers at 7-11 arguing with a customer, but a professor who's job is not to consider the customer is right or placate his customers needs, but rather teach/instruct the students in the best method he believes.
To that end, its really up to the professor to dictate what he thinks is appropriate in the classroom. I think most professors will be open to any method that helps a student learn, but I think with the iPhone many people are concerned that the student's are playing games/watching videos and not learning. Now in isloation this probably not a problem but if someone is playing a game, others may be peering over his/her should and that is disruptive as now other students are not paying attention.
The mentality to always consider someone a customer, does not fit in schools, students are that, students charged with learning not being a customer and to that end a professor really has final say of what's appropriate in his classroom. Of course if anyone disagrees with a professor he's free to drop the class.
I think our differences lie in where the responsibility should settle, and to whether a student is more of a customer or a child; you seem to support a professor centric system where the responsibility of teaching and learning (and dictation of classroom conditions) falls upon the professor, whereas I'm more of the opinion that it is the students responsibility to learn the material, and that the professor shouldn't restrict material based on what they want. If they goof off, play games, or do whatever, it's their fault; the onus of learning the material and meeting the course requirements is their problem. That is in essence, because they're the customer, and, as you said, the professor is just going to do his job. This is where the media usage comes in; as long as it's not disrupting others (which is key), it shouldn't be an issue; the student is the consumer, and in essence the professor is still the "cashier." The cashier may have certain requirements, but as long as you don't cheat, steal, or disturb others, you can generally do what you'd like. It should be noted that the professor is still subservient to the students in the end; if there's too much of a negative response, either through student feedback or skewed grades, there will be administrative action. I've seen a professor denied tenure for it, another one fired by unanimous decision (he had tenure), and another blacklisted into a terrible lab with little to no say in what he gets relegated to do. Of course this happens only with the extremes, but to say that the professor can do whatever he wants and get away with it is absurd; only things within reason, just like the cashier.
It's a bit tangential, but lets look it at from a different perspective. Suppose you go to the movie theater. You're paying for the movie, and therefore are entitled to certain services and standard of quality, yet you can still do what you please within reason. As long as you don't disturb other patrons, you can space out, text, do whatever (again, within reason, as with the classroom), without any impedance. If you don't get the entire experience from the movie, or miss part of it, that's your fault, not the movie theater's. The onus is on you to glean what you will from the paid service, with you being able to do what you like in the mean time. I view education in similar fashion; everything within reason of course.
I guess the point I'm trying to get at is that media usage in the classroom shouldn't be one of those banned or restricted items considered unreasonable for educational use. If they want to use it, even to play games, they should be able to use it; the consequences are their own as they're the paying patron.
