the bridge out to the point looks a little long, and the roll forwards might make it too difficult to defend. unless it starts there, in which case, derpaherp
also the big pool of water is gonna be hell for pyros
I'm well aware of these circumstances. But i can assure you i've given it adequate thought. It only takes 4-6 seconds (512 units) to push the cart across the bridge (give or take number of cappers) which is a fraction of TF2 gameplay and not long at all.
Secondly, water will always make the pyro weak, that doesn't stop map authors using it methodically and with purpose, even in large amounts (sawmill). It is not a rule to exclude water from all maps all the time for ever. Dropping into the water is a tactical choice to be weighed against the protection of the objective by either team and the narrow path increases the power of his airblast. I can assure you the pyro will not be a redundant class in the final battle.