Can my 2012 explorer be repainted or does the hood have to be replaced. The dealership told me that if it is repainted it will just start bubbling and peeling again over time. They said that the hood has to be replaced which will cost me 1900.00
Sounds bogus to me. Check, get estimates from several body shops for refinishing the hood.
If you hood is rusty and that is what caused the paint to fail then, yes, youndo need a new hood. Rust never sleeps and it will ruin the new paint.
It should be able to be repainted depending on the problem. If rust then no, but if just peeling, then yes but would need to be stripped. I bought a hood for a Lincoln Mark for $100. It had a couple dings but otherwise brand new. You can also try a used hood and maybe even find one in the correct color. Car-parts.com is one search site.
Your Explorer can be repainted and the hood probably should be replaced. When there is corrosion problems with aluminum body panels replacing the panel may be the best solution.