Earlier quoted context omitted.
To be against copyright is to not believe the idea of "adversarial copying". It doesn't matter if you like or dislike what other people do with their copies. The act of copying simply does not harm you. The only way people can "abuse copyright against you" is if someone claims you violated their copyright, and invokes a DMCA takedown request, or sues you. You using the GPL will not protect you from this in any situat…
LLMs aid people in abusing copyright by stripping copyleft software of its freedoms and then making derivatives which the author then copyrights restrictively. It's simply not a level playing field when one party is allowed to restrictively copyright their work, it creates a competitive advantage. This is why copyleft exists, to prevent people enacting restrictive copyrights over their derivatives of copyleft works.
But, even in that case, you have lost nothing. Other people doing anything with the code you released, including making restrictively licensed derivative works, does not harm you, cost you anything, or deprive you of anything you already had.