if language is evolutive it means also that language is born with experiment... and it is the own of experiment that all experiences can't be satisfying, isn't it?... so it's only natural that language engenders 'false' expression (in the way of physical 'false' experience not in the way of logics)...
anyway what is the lifetime of an expression like "Mode for Kids" or equivalent? very short isn't it? i'm sure in 15 years of adult-life i have heard many expressions like that (i mean that had this kind of flaws)... but more than one has already disappeared.
so in a way it is only fashion... that's really a more general problem than just a language problem... and IMO i'm not sure it is so clearly related to anglicisation or americanisation of our societies... if it was not english/american words it would be others...
