- Attention to detail: if we care and how much.
- Comprehension of the subject and problem.
- Eloquence: comprehension and mastery of the language.
- Use of adequate tools.
- Are the ideas compatible with the language constructs in use?
Indeed, someone looking at your code can tell if you want to quit, if you're an idiot, if you like being an idiot, if you're awkward and if you should be doing something else.
But in all seriousness, it really tells a lot.
For those actually writing and designing the languages themselves, respek.
I can only strive for it.