For the purpose of argument: If it's a sincerely held belief with the strength of traditional religious views, then what's the difference?
If I don't like Windows, and think maybe I could get out of it if I claim that it's against my religion, that's not a "sincerely held belief". It may be a sincerely held preference, but that's not the same thing.
If I have sincerely held beliefs that, say, closed-source software is immoral, and therefore it's morally wrong for me to use it, that's at least arguably religious.
The problem is to tell the two apart, especially when someone in the first category knows that they have to sound like they're in the second in order to pull it off.
Still, my point stands: Just wanting something, even wanting it strongly, and finding a way to wrap that in religious language, does not qualify for "freedom of religion" protection.
If a religion prevents a person from working on specific days, then that person shouldn't be forced to work on those days, but similarly, a workplace shouldn't be forced to employ them if they can't arrange a suitable compromise (e.g. they don't work Saturdays, but they can cover all the Sundays).