Service and support must be profitable where the product has a long life with a supply of components continuously made or set aside, the standard of the servicing must maintain the original standards of the product.
I do not agree.
Service and support should be set up efficiently such that it's not a huge resource-drain for the overall company, but it need not turn a profit.
It's a perfectly viable business model to say that your service and support departments function to reinforce customer loyalty and insure brand value is maintained. Ideally a service/support department functions so well, and is needed so infrequently, that customer interactions with that department are so positive they serve as defacto marketing.
I've personally had experiences with service/repair on products I owned (outside my day job) where I was so impressed that my likelihood of recommending the product to others, or to personally buy more in the future, was influenced in a way no marketing campaign could ever could. I think about these personal experiences anytime I'm involved with one of our customers in a repair/service/support situation.