Architecture as a profession is so unlike any other profession, because it is not an academically orientated subject (hardly any exams~) and relies an awful lot on practicality and crits, and the ability to comprehend concepts and translate into 3 dimensions and then articulate your reasoning. In school tests for kids when assessors work out IQ tests (usually at 7+ and 11+) they test spatial awareness and a child with poor 'traditional academic' ability can often do incredibly well in spatial awareness, and theoretically show potential for 'massing' and 3d.
Architectural practices are creativess yes but also businesses and in the main have come to accept that terrific students can still make poor employees whilst someone getting a 'Desmond' or even a third could still be really useful at putting together practical technical drawing packages. The portfolio is the real credential that will be assessed, and this will only look stronger if you can kick it off with your practical work experience.
Lets not forget the name sake of the most coveted prize in British Architecture today 'the Stirling Prize,' we will always remember Jim Stirling for his strong contribution to design, and not his weak academic history.