"any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License ."
This reads to me like it requires the entire answer to be published under the GPL.
I guess it does cause accidental violations of the GPL, but in the same way as pasting GPL code without attribution. Or pasting MIT code without attribution.
From a layman's perspective, the only difference is if the comment mixes GPL and some incompatible code in it. But that would be ridiculous under any license, so I actually don't know what to think about it.
