Alan Berman's comments are unhelpful, but I would rather applaud the AJ in setting up this new competition. Given the required subject matter/word length/publication format, what you seems to be aiming for are examples of writing that bridge between academic and journalistic modes. It is an undoubtedly fertile area, and one in which Reyner Banham was the acknowledged master. But let's not pretend that it constitutes the whole field or purpose of architectural writing, and anyone who has read Banham extensively knows that he never made that mistake.
As Jeremy Till and John Bold point out, there are already important annual competitions that are encouraging truly excellent work from young architectural writers. These are the RIBA Dissertation Medal, whose winners are then published in The Journal of Architecture, and the RIBA President's Award for Outstanding PhD Thesis. If the new AJ competition can promote another area of writing, then so much the better; let's make a thousand flowers bloom.