I don't ask my users to install Visual Studio, IIS or Windows Server 2012 on their boxes. I kind of think asking them to install SQL Server is similarly foolish - particularly since now you have to pay for 1 SQL server licence per user rather than 1 per organisation.
Have you heard of SQL Express?
If you're going for edge case business scenarios as your rationale as to why RT isn't a good choice, perhaps you should be considering whether Windows8-Pro is more appropriate for your business needs than Windows-RT.
Windows-RT is never going to be a good fit for where you're forced to use desktop applications, supporting services or plugins to existing applications and can't provide equivalents as a web-service.
RT vs. Pro really isn't at issue here since the database discussion is about the limitations of the WinRT / Store App API which is on both RT and Pro devices.
I don't know what marketing has to do with it, but, at least as far as the database issue being discussed here, a valid criticism of the limitations of the WinRT API with regard to database access was brought up and it didn't seem in any way vitriolic. What I find amazing is that people on this forum can't possibly fathom an application that downloads data from the Internet, stores it in a local database, and then does reporting and analysis on that local database. Really?