The BBC Two comedy, also written by Stephen Merchant, has been accused of exploiting its lead Warwick Davis.
Gervais tweeted: "People need to see the difference between programmes that satirise/highlight/reflect exploitation, and programmes that actually exploit."
The Office star then told Davis on the social networking site: "I love how people respect your right to BE a dwarf but not PLAY one on TV. How dare you? Be small in private OK? Sicko!"
Life's Too Short's audience figures have declined since its premiere over three weeks ago.
Watch Warwick Davis talking to Digital Spy about political correctness below:
