When I was a city rider to commute, pads alignment was a real PITA and the main reason that made me switch to disc brakes. I was always feeling braked and spending more effort than really needed because one pad was touching the rim. With disc brakes that feeling disappeared and never came back, although you still need to do some maintenance from time to time.
Heh, yes, less maintenance, but also less finicky.
Brake pads on rim brakes are a nightmare. They follow a 3-d arc as they approach the rim, which is itself a very complicated 3d surface. Ideally the front edge of the brake pad hits slightly before the rear edge, to avoid squeal... but not too much or it will engage too softly. Even minor wear changes the engagement point. Cables need maintenance, they wear, get kinked, require lubrication, and it's easy to get the tension wrong.
It's all a mess, and even when perfect, and it's dry, not too cool, not to hot, not dusty... they still get worse with every use.
On discs it's more like replace the pads when worn (no adjustments, just remove the pin, pull the old pads, push the cyclinders in, put in the new pads, and put the pin back in). Sure there's occasionally a need for replacing brake fluid and/or bleeding. But generally way less maintenance, and you get like 90% of perfect braking all the time instead of 10-90% depending on temp, wetness, ice, grit, state of tune, etc.
I personally think that mountain bikes with slicks make for a great commuting bike. Fast, stable, low maintenance, and shrug off curbs, steps, and potholes. They also tend to be (on average) more upright for better visibility of the road. Also the brakes are available in the up right position, unlike some road bikes. Never know when a car is going to want the piece of road you are on, it's nice to be able to hop onto a curb.
Also MTB's generally accommodate the widest tires, except for fat tire bikes and generally wider tires can be very helpful when commuting for comfort and making things like a random rock or walnut much less exciting when you hit them.
Commuting with rim brakes inevitably destroys the rims, try commuting for 3-5 years then closely inspect your rims, little micro cracks are not uncommon, and will get worse right up until you have a rim failure.
It's also really nice if you do hit something hard enough to knock a wheel out of true, that you still have two working brakes.
Once you've used hydraulics, you never want to go back to cable. They are so much better on all counts that the tiny weight gain pales into insignificance.
