This is why I work multiple remote development jobs. If one traditional job is good, > 1 is better. It would take a quite a successful SaaS to pull down what I do annually.
Multiple full time jobs at the same time? Kudos for pulling that of... though, as a founder hiring remote people from time to time, this is also a bit terrifying.
If they get your work done, don't worry about it. If on they other hand you don't know what the work is you want done, and expect a developer to come in and do it all, don't worry. We moonlighting devs won't even apply for your job.