I think the reason people find this so difficult is that only being able to shoot horizontally is a fundamentally bad idea unless the level design is heavily geared towards it.
In a narrow vertical passage, dashing is both my only practical method of attack, and the best way to dodge enemy bullets. The problem with that is that it takes about two seconds to recharge, so after I dash into an enemy, I have basically no way to properly dodge the attacks of the remaining enemies while I wait for it to recharge.
tldr: Using the dash as both a dodging tool and an attacking tool at the same time isn't feasible because it recharges too slowly.