I'm a founder too and had a story similar to yours. There's much more to working at a company than cash and equity: Learning fast, good people around you, climbing up the career ladder much faster, freedom and autonomy.

It's just when you've got neither of these perks that you should start searching - because if you don't have that side either, you could as well go to a high paying corporate job. And then I'm on the side of the employees: Loyalty is important, but it's not a one-way street.