Ordinary aircraft aren't compatible with carriers--you need a tailhook to land, at the very least. You need significantly more talented pilots to land on carriers. You need billions of dollars in aircraft carriers. (The most extravagant navy in the world has about 12. How many carriers do you need to make an airline out of it?) The shock of catapult-assisted takeoff is not for everyone; the passengers would need to be in decent health. Add all of this to the fact that airlines are only marginally profitable in the first place, and it's just completely infeasible.