Rust feeds rust. It provides crevices and "shelter", if you will, where moisture, salts etc. can hide out and eat at the blade. Polishing removes all the "hide-outs", making it very easy to wipe off the salts and moisture. A freshly polished blade will always resist corrosion longer than one that has meerly been "cleaned".
Caring for carbon steel blades is not difficult. They won't rust up in a few minutes, but, once used for some time will develop a greyish coloured coating (described as patina). That coating is somewhat protective, and can be forced with any acidic food product (vinegar, onion, orange, lemon).
What rusts carbon steel blades is being left wet, or left in a damp sheath. They will rust badly in a day or 2 this way. Luckily, it cleans up with a scotchbrite pad in a few minutes, reverting to the mottled grey patina.
I forge knives from spring steel. I use a trio of them in my kitchen EVERY DAY. They get tossed in the drawer with everything else. I'm careful to clean'em immediatly after use, with HOT water, dry them immediately (the hot blade finish dries itself in short order) and I lay them in the drawer edge down so that no drops will sit on the face of the blade....
With simple, proper care, carbon blades give great service. Only the careless and unkempt find them troublesome.
J