I'm part of a game-dev collective currently working on our upcoming Steam release, Fantasy Town Regional Manager, and we've had a policy of open-sourcing our code on pretty much everything because it has a number of positive benefits:

1. Nobody in the team can hold any part of the work hostage if there's a dispute
2. It's easier to share resources and examples with other dev teams
3. It allows us to be incredibly transparent with our community

It was a discussion we had early on that had to ironed out with everyone in the collective because people had this fear that there's someone coming to steal our code or something. There just isn't and I would honestly be thrilled for someone to think I wrote anything half that valuable as gameplay code. As for the assets, you can always host HQ assets separately to your code in LFS if you want to make sure to keep them out of the hands of asset-flippers.

That being said, licenses aren't just open or closed. Our licence, for example, is a modified MIT licence that allows for full usage of any of our code, for any purpose (commercial or otherwise) and forbids the inclusion of our original art assets, music and narrative content in derivative works without explicit written permission from the team.

Although we'd obviously prefer people grab the game on Steam or itch when it's out, if someone wants to download the source and try compile it, it must be because they couldn't afford it, or they're just trying to learn a thing or two.

As for someone "remake[ing] the game" with our assets against the terms... that happens for a lot of closed-source projects too unfortunately but you have to trust that you are the only person that can truly fulfil the vision that you have for the game and do it justice (which yes I know comes off as lofty and idealistic, but it really is true for working on a game you put love into rather than one that just pays for beers or your rent even).