Judging by the TV coverage the stadium seemed pretty quiet, it wasn't a great game either. I suppose the whole Team GB for football doesn't sit easily with many football fans, and Olympics football is pretty low on the priorities for football fans at the best of times so perhaps the relatively limited interest isn't that surprising. Interest probably won't pick up until GB play Brazil in the semi final, if GB beat South Korea and progress.
For British fans today belonged to Helen Glover, Heather Stanning and Bradley Wiggins, so that is probably the biggest reason why there's not much talk of the football, the sports fans interest is elsewhere right now.