The small amount of time spent on writing the parser might have something to do with how well-understood that area of computer science is. If nobody had ever written those books which were mostly about parsing, then maybe writing the parser would be the hardest part.
I don’t think so. Almost everyone abandons all the theory and just writes recursive descent. It's not the case that they're using it but have just come to see it as normal. They're not using it.
Yeah, I always write the grammar before writing the recursive descent parser. I can't imagine doing otherwise. It would be a mess.
I'd go further and say that for most people, the first time you read or write a context-free grammar is when you're trying to write a parser. So the theory is motivating the practice.
