While I can agree to the argument made by mnem, I still would like to have that tag. After all, a tagging system only earns it's merits when there are many, potentially overlapping terms. Otherwise it degrates into a simple classification system/list.
Second using only 'specific' tags doesn't help against tag piles. They are still prone to overlaping. Just take for example this question about Apples floppy controller (and controllers in general). Beside the Disk II tag (*1) there's the Apple II tag. For a strict system it would need to be removed, but then again, this question might as well be of interest to people seatching information about the Apple II. Much like the CPU tag - when people look for question related to CPUs, not whole systems or perhiperals or whatsoever.
So give generic tags a chance.
*1 - I still think the usage of psudo numerals or any kind of marketing related spelling should not be encuraged in RC. After all, it's not just II with the apple, but also II+, IIplus, //c, //e ||gs or ][ (and ÜÄ :)). So Apple 2 (or Apple2) would be way more fiting as general tag for all machines of the II series. The reason that tags are unified all lower case is to get rid of spelling games.