Is the expression 'too much, too young' grammatically acceptable?
Solution 1:
I don't think it's justified. It looks and sounds like idiomatic English to me. Don't we have an expression that goes "Too much, too soon"? In addition to the movie, there's this song Too Much, Too Soon, this Brookings Institute report on foreign aid to Burma/Myanmar, and this Wall Street Journal article on Google Glass.
The caviler is a misguided pedant, IMHO.