Why? Cuz they don't always make the character you like more win the fight?

No by being objectively wrong, and coming up with retardedly one sided matchups, and still being wrong about them sometimes.

Which ones are "retardedly" one sided?...

Batman Spider-Man Master Chief Doom Guy Rogue Wonder Woman Mario Sonic Doom Vader Flash Quicksilver

Ok the only ones out of those that are particularly one sided are Vader vs Doom and Rogue vs Wonder Woman. Vader can just force choke Doom or pick him up with the force and repeatedly slice him with his lightsaber. All Rogue has to do is touch Wonder Woman for a few seconds, cuz let's face it, WW doesn't exactly stay particularly covered up... Plus they don't exactly choose the match ups... They take suggestions from the comments and always show a few of the commenters that gave that specific matchup at the beginning of the video.

If you don't know anything about the canons being discussed, why even try to talk about them?

I don't know how my phone works and I still use it and talk about it... Plus I highly doubt there's people that know everything about every character. And I don't claim in the slightest that I'm a know it all when it comes to this subject and I know I don't know much about dr doom or fantastic 4 in general - they don't really interest me much. Xmen however... Rogue is a f*cking badass! And even without her lifesteal/power steal ability, she'd still be able to give Wonder Woman a good run for her money because she has super strength and can f*cking fly!