Wow. That all sounds like me.
But really, yeah, I'm aware I draw rattata more scraggly than most do, but it's on purpose. There's no lack of cute rattata artwork, and there's not enough people who view rattata as cool or awesome so I go for that look >w< I WILL SHOW THE WORLD RATTATA CAN ROCK TOOOOOOO!
Don't sweat it, man, I hear ya. I know there's an abundance of cute Rattata art and I'm sure I'm not helping. But sometimes you gotta show a different angle. The way all of our interpretations balance each other out is what makes fan contributions to Pokemon so good. What you do for Rattata, I'd do the opposite for a Pokemon like Nidorino, or heck Raticate. "Overly vicious looking? Nah, they're not so tough! How can you resist this smile?" I try to show the cute, friendly or funny side of Pokemon.
I've always liked normal types, they always seem to get so little love, but they have some of the cutest designs, and I also feel that a lot of their designs are much simpler than others, especially in the more recent games. I like the simple and elegant designs over lots of frills and colors, so I've always liked the more mundane normal types in general.
That's actually an important factor of character design. Maybe more western in practice, but nevertheless.
I had very little idea about actually designing my team for type coverage or battle strength, so rattata/raticate always stayed on my team for the entire game, elite four and all. I guess I heard so many people talking about how it was a terrible pokemon and getting rid of it on their teams so I think I developed a stronger love for it defensively.
Actually that may account for my tend to like very underutilized pokemon in general. I don't care much for stats and battle technique that much XD
Even after I've figured out strategic battling, I still usually played with favorites instead, and probably had at least two of them in my team. I can't say I've kept Rat(tata/icate) on my team for the long haul, but if Nidoran Female is obtainable during the game's initial campaign, you can bet I had a Nidorina for the rest of the game.
The other two points about liking underused or underappreciated Pokemon, and liking them more because others snub them off are also something I can relate to, both Rats included. It helps that I like rodents iRL so they have a bias in their favor. My favorite Pokemon family, generally speaking, is the Nidoran family, but I seem to be apathetic to Nidoking solely because he doesn't need me to vouch for him, and probably drawn to Nidorina the most because at the time, she really needed all the help she could get. It's not nearly as bad anymore, though.
Other Pokemon get this reverse popularity treatment from me as well. Dunno why I feel like I have to advocate for them, I just kind of do. :\