Just because they're experienced doesn't make it a great argument. Additionally they generally articulated more substantial concerns than "it looks weird."

To be exact my argument is that strange syntax does not increase the complexity of the feature. The complexity of async/await, especially when compared to features like the borrow checker as CJefferson complained, is in its semantics. You need to learn general async/await semantics like the fact that awaits always have yields regardless of which side of the expression you put it on among other things. And a number of rust-specific complexities that are very different from other languages (cold by default futures, executors vs reactors, pinning, etc.)

Neither does saying "this is a pretty lazy criticism that doesn't hold water for anyone who's spent more than 5 minutes looking at async Rust code." It clearly does and did.