From a manufacturer’s standpoint, it’s better to minimize salt and give the customer the flexibility to season the pasta water, or sauce, as they want. I am curious though— gluten, texture, etc. notwithstanding, i wonder how much salt you’d need to add to a pasta dough to get it to taste the same as an unsalted pasta cooked with 1 Tbs. of kosher salt per quart of water (Dan Gritzer tested different salt to water ratios, and preferred 1-2% .
As @PhilD points out, there are structural consequences to adding salt. Harold McGee in On Food and Cooking says that salt in the water adds flavor, limits starch gelation, and reduces cooking losses and stickiness. When talking about Asian noodles, he says that salt tightens the gluten network and stabilizes the starch granules, keeping them intact as they absorb water and swell. Very interesting. So, salt helps the pasta, but hurts the pasta water (assuming you wanted to use it to thicken a sauce).
Page 478 of an article on industrial Asian noodles confirms what salt does to dough. A zero to 2% increase in salt improves sensory evaluation scores, especially for low-quality flour. Salt decreases water absorption and increases the dough development time, results in a more uniform gluten structure, leads to an avoidance of strand breakage, toughens noodles during the sheeting (rolling out) phase, and increases yellowness but decreases brightness. However too much salt isn’t good. They don’t go into detail, but say that high salt (>3%) results in deterioration of raw noodle rheological (flowing) properties.
