Clarity is important but I don't see how it suffers from that except for people reading code in that language for the first time. To my knowledge the languages shortening this to one letter are also the kind where the programmer can be expected to already know the fundamental data types, otherwise this syntax won't be the biggest problem.

Personally I prefer it, mostly for subjective reasons but I think it makes sense - in the case of Rust it was the easiest syntactic novelty to get used to, things like lifetime annotations are a different beast.