Not many people just come out and say it, but I think Rust is an ugly programming language. That's a good enough reason for me.
It's much easier to invent a complicated tool and come up with excuses about why all the complexity was required than to invent a tool which makes people happy and productive. Of course some people are rather weird and they're happy with baffling tools, but I'm talking here about the majority. Garbage collection is the kind of invention which freed countless programmers from having to painstakingly worry about memory management. It's not perfect, as it doesn't handle all resources, but it is doubtlessly a step in the right direction.
Now if you look at Rust, their solution to memory management is to force the programmer to add countless annotations so that the unintelligent compiler can figure out what's happening. This is a step in the wrong direction and I certainly hope that this is only a local optimum that will be surpassed, otherwise the future of system programming looks quite sad.
Every time I think of the ugliness of Rust, I'm reminded of the comments from Stallman where he acknowledges the elegance of Java as an evolution of C's syntax, even though he never reached for Java for himself, having always stuck to C and Lisp instead. Then he goes on to trash C++.
• Rust wants to have easy-to-parse unambiguous syntax. This makes turbofish required when you have a type in expression context. You need `->` for the return type.
• Rust uses generics, and angle brackets are ugly. It also mandates `{}` in blocks, but allows skipping `()`, which gives you a high ratio of ugly brackets to the nice round ones :)
• Rust wants to make up for the cost of explicitness by adding abbreviations. So you have `fn` that's both explicit and terse. Instead of verbose `switch/case/default`, Rust's `match` uses patterns and `_ =>`.
Rust designers pay a lot of attention to the syntax, but it's designed from a very practical point of view (it is clear? unambiguous? easy to write? composes with other syntax?), and "does it look neat?" is very low on the priority list.