The artist cited "editorial battles" and colleagues' failure to meet deadlines as partly responsible for his exit from Hawkman, Deathstroke and Grifter.
"I had at least 20 editorial battles and won 80% but those battles wear you down," he wrote on Twitter. "Everyone kept covering for another guy who kept slipping and tripping all over his deadlines. Excuse after excuse… then, silhouettes.
"Just don't believe I'm rewarding the guy who draws silhouettes after silhouettes and makes his inker draw his pages. Sorry."
Liefeld went on to say that he did not feel "important" to DC, but hailed the company's 'New 52' initiative as a "positive for comics".
"Reason I went public hours after informing DC is because I did not want anyone controlling my news but me," he added. "And I loved all the work I did there regardless of the struggle. I think the DC 52 was/is positive for comics."
Liefeld will now focus on his creator-owned work for the remainder of the year.