..and will be atleast 5-10 levels higher than Gyarados at the point you would meet him.
This is the only line I disagree with you on, because it is heavily reliant on play style. If you tend to favour one or two pokemon, I can see being that far overleveled. However, if you were to raise 6 pokemon evenly without wild pokemon grinding, just trainer battles then Gyarados would be more about on par or even at a higher level, rather than a hindrance. I'm not saying you are wrong, just that it isn't absolute.
Also it being hot shit is most likely because it is shiny. Even if it is a predetermined-everyone-gets-it shiny, it is still a shiny.
Personally I could care less. I've used Gyarados in too many various runs over the years that it is really boring to use it again. Feraligatr is where it is at.
EDIT: In retrospect it seems I was doing a devils advocate, sorry if it felt I was arguing for arguing's sake, that wasn't my intent. You did say it best:
Point and case-it comes down to personal preference-nothing more.