I spent quite a few year on/with it back in the day. There was D1 which was like a better C, and then there was D2 which was like a better C++. Personally I preferred where D1 was going (and Tango instead of Phobos) but even with D2 it really made the day compared to what was out there and to this day still to an extent is. The thing that killed it for me, and I know at least a couple of friends as well (outside of internal politics at a time) was what kills pretty much all exotics once you start using it. Lack of (up-to-date) libraries / bindings and tooling. At the end of the day that's what you do use for most of the work you're doing anyways - libraries. So suddenly you're doing all these bindings and battling tools instead of working on actual problem at hand. This gets tiresome real quick.

For some reason, and mostly that being Mozilla, Rust got quite an initial kick to overcome that initial hurdle in haste. We're not going to mention a lot of those libs are stale in Rust world, but at least they're there and that kind of gives you momentum to go forward. Whatever you're trying to do, there's a non-zero chance there's a library or something out there for you in Rust.. and we got there real quick which then encouraged people to proceed.

That's just like my opinion, man.. but I think a key part is that first lib bindings hurdle which Rust somehow went over real quick for a critical mass of it; D hasn't.

Love the D though lol, and Walter is a 10000x programmer if you ever saw one but it might be time to hang the hat. I can only imagine how a community like Rust or I don't know Zig of those up-and-coming would benefit from his help and insights. He'd probably single-handedly make rust compile 100x faster. One can hope.