You’re seeing this because this is currently the industry trend so you assume the last two years is how it will always be. It’s all you know. After seeing this industry for 30 years I’ve seen advantages to both and phases with both. I’ve seen those holding airplanes, such as ACA, not being able to shop them and going under after a short stint of trying to go as an independent.
Regionals don’t just print money to buy airplanes. They have to finance it. They have to find investors willing to purchase those airplanes and finance them. If people feel they can get a greater return on their $ than airplanes they will take the money elsewhere. The cost of operating then goes up. For smaller airlines such as regionals this may be too much to handle.
Legacies now are able to still play regionals off against each other. Look at the AAG WOs. They haven’t combined them and they probably won’t. They will play them off against each other and against the independents. They will never combine them and permit another Comair. Scope will limit the number of aircraft that can be put on line.
Eventually, we will probably get down to each legacy having one or more WO and probably 3 large independent regionals. They will continue to be played against each other. Some will see airplanes fielded, some will see them taken away. But it will be a shell game.

Finally, I would add that when you’re talking about an airline “owning” aircraft you are usually talking about an airline leasing aircraft. Check the registration. Many times you will find a bank or leasing company on the registration. I think K4 was the only company I’ve worked for that owned almost all their aircraft.