At a research university, if the customer is paying for the brand name recognition of a quality research school, but I spend all my time teaching at the expense of being an active member of the research community, they are not getting their dollar's worth of brand name value to their eventual diploma. Researchers should remember that they are doing their job by being good researchers, not just because that's part of why the university pays you, but by doing so, you are acting in the customer's interest by not deflating the value (here, reputation) of their diploma.
I’m not sure why people see the "students-as-consumers" vision as such a bane. Instead, just follow it to its conclusion. Teaching well and grading fairly are both part of the contract. Inflating a grade or doing anything to over-service one student at the expense of the others is a disservice to the vast majority of your customers. In short, it's more like a tour guide than like a class at a health club, and certainly not a like a personal trainer.
Also, what you're selling is not something that's intrinsic to them (e.g., good abs) but whose value is in the school's reputation, as decided by the community. Therefore, attention to one customer at the expense of the others - or failing to maintain your research reputation in the service of one student - is not good customer service.
I think one reason the student-as-consumer paradigm evokes so much distaste is the degree to which it reflects much of the customer/service provider interaction in American culture. Sure, in a perfect world, people would realize that when they are denied special exemptions, that's because all customers are treated with one standard, and that fairness to the whole customer base is laudable and a sign of a quality business. But this isn't a perfect world. Instead, the mantra of choice is often "the customer is always right", and for many (not all, but enough) customers, that means demands of special treatment above and beyond what is reasonable for a business, let alone fair for the customer base as a whole.
The principle operating here is that the customer's potential revenue allows them to dictate the terms of service in a way that benefits the customer most, regardless of anyone else. I saw plenty of this as a copier jockey while I was an undergrad. Anything from demanding ridiculously deep discounts on jobs that weren't that profitable to start to impossible printing jobs to just cutting in line ahead of other people. At its core, I don't see that as being much different from demanding a better grade or unreasonable makeup opportunities and deadline extensions that the rest of the class doesn't get. And in my experience as an instructor, when you try to explain the fairness side of the issue to the students doing the complaining, they just don't hear you. "Fair" doesn't enter into it for them. "Fair" is for everyone else.
Besides, there's something about the use of money as leverage in a customer service situation that strongly resembles a master/servant relationship, where the customer service provider - held hostage to the dollar - is just the hired help. And you know what? Teachers in higher education may be many things, but we aren't the hired help.