Slime did that? Slime doesn't take over the editor that much (it shouldn't prevent you from typing parentheses, I've used it for 16 years or so and never experienced anything like that). Was it paredit or another editor mode?
I guess my point is that syntax that works very well with a correctly configured editor used by someone who knows what they’re doing is going to have a higher barrier to entry than a language that can be easily edited in Notepad.
It’s a lot easier when the editor highlights matching pairs.
Not even English.