I think he did not think it would make such a big splash.... When he realised it, he already lost the private key to the coins he mined as part of the experimental in the beginning.

Then Gavin went to speak to the 3 letter agency and he got spooked and he dropped the whole project.

If he was still around, he would have been in court for most of his days. I think there is no sinister motive behind these coins... It's just a experiment with lost results.

*The he, can be replaced by she / they / it