> We believe in Open Source
But you don't believe in it enough to do it.
> I'm surprised people generally take the binary view that either Open Source with no protection or go proprietary completely
Because FOSS is about community contributions. People contribute to something owned by the community for the good of the community. Yet here you have claimed the near-exclusive right to profit from the code. FOSS is saying that you expect some of your users to contribute to your code, so you are effectively saying: "contribute to my code for my benefit, and I might let you use it in some circumstances" which is antithetical to the FOSS saying "contribute to public code for public benefit".
> Nothing, you can do that!
Then why not let people free-load of the current version? The answer is because you want to be the only ones who profit from this software. This license exists to keep you as the soul or primary beneficiary of the code for the duration of time you are developing it, unless you make a decision so fundamentally bad that people are willing to wait two years to fix it. I'd wager you don't think you'll make such a decision.
FOSS is explicitly about letting anyone do anything they want with your code, even if you don't like it[1].
[1] https://www.gnu.org/licenses/gpl-faq.html#NoMilitary
> More generally, a license that limits who can use a program, or for what, is not a free software license.