That's nasty. That's not how developers should work. They should
1. Finish Video Game Franchise 5
2. Start working on Video Game Franchise 6
3. Finish Video Game Franchise 6
4. and so on.
I'd understand if they stopped working on Rust but this is just stupid.
I hope you are joking. Think about what you're saying. That's not how game development works. Just in case you weren't taking the piss (or for other clueless people in here who definitely weren't), consider this:
Think about the different disciplines involved in game creation nowadays. Think of a concept artist, for example. He's done his work on video game franchise 5, his paintings are done, the level designers, environmental artists and camera placers know the vision for the levels, know the colour pallette and mood they're aiming for. His model concepts are done. The team has decided on the look of the characters and enemies, the modellers and texture artists are hard at work. So here are still a hundred people working on video game franchise 5, but the concepters work is done.
What is he supposed to do? Wait 6-12 months until video game franchise 5 is completed before he starts his work on video game franchise 6?
Now, this case in particularly doesn't 100% apply to the Rust devs, as they're a small team and I assume everyone has multiple roles to fill, so their concept artist guy might also do some texture art, or might do something else for example.
But game development is fluid, and especially smaller teams need to maximise the efficiency of every one of their employees. So when it doesn't make 100% sense for one person with a specific skillset to still work on Rust, his talents are maybe best used to prototype their next thing.
Now whether it's smart to announce this next thing publicly while their previous thing is still in early access is another matter entirely. But I think considering how open the Rust devs have been about every design decision and considering that Rust is still getting worked on, being continually updated, most people with a modicum of understanding on how game development actually works would appreciate that honesty instead. I assume those bitching aren't really thinking about what's happening and are arguing out of ignorance.