I hope I'm not the only one who remembers these seven hecklers.

Nintendo has this really stupid habit of introducing awesome characters with personality, then totally ditching them a few games later, especially in the Mario universe. (They also like to introduce lame characters like Waluigi or Petey Pirhana, who have no discernable personality or backstory, but that's a bitchfest for a different day.) In Super Mario 3 and Mario World, the seven Koopalings Larry, Morton, Wendy O., Iggy, Roy, Lemmy, and Ludwig Von wreaked havoc all in their own way. What was so great about them was that they each had their own personality that made them shine.
Larry made up for his physical ineptitude by being clever and tactical (Shown in his SMW boss battle). Morton, every bit as bright as a brick, would constantly try to beat Mario and prove to King Dad that he didn't suck, but always lost in the most hilarious way. Vain Wendy O. desired pop stardom, had a big head, and considered herself too important to battle Mario. Creative Iggy was the genius, able to build and create clever traps that littered his dungeons. Roy was a powerhouse and loved to show it, often by bullying his siblings. Lemmy was the comedian of the group, and both his small size and carefree attitude made him less than interested in fighting Mario. And finally, Ludwig Von Koopa (My personal favorite), the musical prodigy, was profound both intellectually and physically, making him one of bowser's most trusted and dependable minions. (Additionally, Ludwig was the only Koopaling in Mario World who didn't try to cop off an earlier boss fight, and was the only one who developed Bowser's Fireball technique.)
So after starring as seven challenging bosses in Super Mario World and Super Mario Bros. 3, what do you think happens? Nintendo erases their entire existence. They deny the Koopalings ever existed. Apparently, the Koopalings knew too much, and Nintendo just had to deal with them somehow.
Along comes Bowser Junior.
Let's read that again.
BOWSER. Fucking. JUNIOR.
If that is not the most creative name for a character ever, I've yet to hear another. Continuing Nintendo's pattern of taking out awesome characters (Like the Koopalings, Kamek, or Tatanga) and replacing them with pointless characters who lack any personality and no one possibly cares about in order to provide some lame sidekick (Like Princess Hi-I'm-Daisy), Bowser Junior is introduced in Super Mario Sunshine. While Sunshine was definitely one of my most favorite Mario's ever, Bowser Junior--everything about him--made my eyes twitch as though they had developed minds of their own. His irritating, whiny, scratchy voice. His lame "I'm a little Bowser nyyyooww-nyyyooww" design. His boring, little-explained character history. His trite dialogue. Everything that made the Koopalings awesome (Diversity of personalities, cool character designs, memorable boss battles) is thrown out the window for some minor character who does nothing more than annoy you at best.

Listen, I might sound like I'm bashing Nintendo or whatever, but let me make myself clear. Nintendo makes some very awesome characters. Link, Mario, Midna, Zelda, Luigi, Donkey Kong, Ness, Captain Falcon, Fox McCloud, Falco Lombardi, Wario, Ashley, Krystal, Yoshi, and the Koopalings, just to name but a few. The problem I'm bringing up here in this Artist Monologue is that Nintendo has the tendency to throw some of their best or most promising characters aside to put characters in the spotlight who just don't deserve to be there.
You can say what you want about Sonic or Megaman having too many characters, but at least SEGA and Capcom take the time to flesh those characters out. As they are now, we're only keeping Waluigi and Tingle around as punching bags.