Under the OSIs definition of open-source, and under the definition of free software, anyone can buy your software and redistribute it to others for free. This effectively limits you to earning money only off the labor of your work, not the work itself, and makes your business model effectively useless. This is such a huge difference yet the FSF, as always, confuse people (maybe even intentionally) by saying that free software can be commercial. No, it cannot. The services you provide can be, the labor you provide can be, but the software - no.

You can remove that freedom to the user. After all, the source is available, it can still be tested for malware, but your work won't be open-source.