Free Software has nothing to do with getting paid for developing it.
It is about the freedom that comes with it.
Proprietary software restricts the user’s (or customer’s) freedom to have control over what the software does.
Free Software allows the user, or the customer, to have full control.
This may seem unimportant to most because they lack the knowledge and skills to actually do much with the freedom that comes with free-software, but Free Software is about an ideal, not really a coding practice (as Open Source simply is) or a business model.
Free Software can be free of charge or paid just like proprietary software, a user can be asked to pay for services like professional support or ad-hoc customization and consulting.
But regardless of what business model the developer(s) choose(s) to employ, free software will always allow, unlike proprietary software (free of charge or not), anybody to have control.
I understand that the terminology doesn’t help and this is a known problem, the word “free” means both freedom and gratis and software can be both or none or either, therefore the only thing that matters, for Software Freedom and, I suppose, for the purpose of this thread, is that software must be released under a Free License.
So no, developers of non-free software are not evil because they put a price tag on their products, in the same way as developers of free-software are not sellouts when they ask for money to let others use their products or to work on other’s free-software.
Whether developing non-free software is evil in itself, I leave to you to decide. Personally I feel proprietary is the dark side.