Yep, that's what it comes down to basically is laziness. The people using ChatGPT to write their posts aren't going to bother with changing the text to make them not look AI-written. Case in point:
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This user was actually banned for plagiarism... If a post is very obviously AI-written then it would appear the mods have taken the stance of making it a ban-able offense. Good.
I'd say, ban everyone who uses ChatGPT to impersonate a human.
Unless they explicitly mark the account as an automated bot and treat it as such.