1. OMG you finally have a dad! And he's actually employed! AND you get to fight him later on and get a feeling of "Wow, I just surpassed my own father!" I was glad they finally implemented the main character having a father, and having some relevance to the plot in a fun way. Too bad they never gave the protagonist a father again. WTF why not?
2. He has a simple design and is not over-the-top ridiculous with his appearance and poses, like a lot of later gen Gym Leaders seem to be. He's just a plain ol' looking dude, which is fitting since he specializes in Normal-type Pokemon. Simplicity is the best.
3. He uses Slakings and a Vigoroth, some of my favorite Pokemon out there. I also found him really difficult when I was younger. Maybe not too much now, but I genuinely would have a tougher time with him than I did with gym leaders before and after.
Thinking about Norman made me realize that Emerald has the toughest Gym Leaders I ever fought :/
Norman's difficulty is entirely based on whether you abuse protect. Slaking has the stats of a legendary (and Norman has two of them), but he's infamously predictable. The rest of his team isn't nearly as challenging.
We're the only Marvel title that features squirrels. And do you really want a squirrel-free comic? I don't think so. - Dan Slott, on GLA