You can test that for yourself. Go through the three language-related sections on my site and decide for yourself how many hours you'd need to "waste" before you would "get it".

And as for "waste" : if while learning a better language, they are in addition also learning the relational model, and to think relationally, (their knowledge of both of which will be VERY poor if all they've ever seen is SQL) then there can't have been much time "wasted", can it ?