Nobody is forcing you to buy a maemo phone. If you trash your Iphone with a bad install of something, you have the same problem.
Nokia having a Maemo phone available doesn't mean you have to stop using your Nokia tablet.
p@marketing has already told us they want to stop associating the word "tablet" with their Maemo products. This may or may not mean that they won't make more of the larger ones. Shame if they don't. But I don't see a problem with there being Maemo phones on the market.