The push to eliminate lifetimes in favor of loans (with this or polonius) in the pursuit of allowing a larger subset of correct programs to be expressed in Rust makes sense at first blush — of course we want to be able to prove more correct programs correct! Who wants to fight the borrow checker all the time over things we know are fine! — but I'm concerned in the long run it will actually turn out to be a bad thing.

I vehemently disagree with the article that lifetimes are at all nebulous or hard to grasp, IMO they're a pretty straightforward concept, and they map really nicely onto single ownership, move, RAII based memory management, and underlying C style memory management concepts, whereas OTOH it feels like loans are perhaps less nebulous, but also map more poorly onto the best comprehensible, and specific ways to think about low level memory management (and also less well to concepts in other low level languages lile C++). Instead of seeing your program as a mostly 1D collection of mostly contiguous scopes that the program counter jumps around in, now you have to view it as a gigantic thicket of constraints.

So in essence, by making Rust's static analysis more powerful and less annoying at first, we're actually making it harder to fully grasp in the long run. It's sort of like the Haskell monad problem — the more powerful you make your compiler/language abstractions to allow proving more code, the less comprehensible everything gets. And I think in both cases, trading some power, past a certain point, for long term comprehensability with more straightforward concepts is better.