Who is Rob Liefeld and why is he called by many "the biggest dork" to ever make it big in comics?

[Thundarr the Barbarian]

Many claim that he all but single-handed destroyed the comic book industry and that it has never recovered.
What is the history behind this event?

[Billy Bob]

Probably because he has a really big dork!

[Rebel With a Cause]

He was a very prominent artist for Marvel during the 1990s, and the co-founder of Image Comics. He is also the co-creator of the Marvel anti-hero Deadpool.

Currently, criticism from modern readers are towards his writing abilities and his outdated art style, specifically his lack of attention on human anatomy. He is well aware of the criticism, but he doesn't care.
Recently, when he was on Twitter and while working for DC, he publicly went after the DC editorial staff. Soon after, he quit, or was fired, from his DC titles(Grifter, Hawk & Dove, Deathstroke). Another Twitter highlight of his is when he argued with Scott Snyder, the current writer of Batman and Swamp Thing

He didn't single-handed destroy the industry, but he did have a hand in it. In 1992, he co-wrote and drew the new series Youngblood, the first comic under Image Comics. Because of the hype around the series, as well as the attention of the high profile Marvel artists and writers now working for Image, Youngblood #1 was one of the best selling comics at the time, rivaling DC and Marvel.
However, the comic was trashed by critics, but the sales fueled the spectator market. To summarize what the market is, collectors bought comics purely to sell them at a higher selling price. DC and Marvel helped this market, with gimmicks: die-cut covers, multiple variant covers, glow-in-a-dark, etc. Long story short, there were too many books on the market, each selling beyond the cover price. As a result of too many comics and not enough readers, Marvel filed for bankruptcy in 1996.