My father does radionucleidic metrology and every time there is a breakthrough at all, be it JET or something else, total rejection that it was a big deal or "real" or that its "not a large enough net gain reaction" to matter. Its wild

I think scientists are humans after all and they (much like people who rejected bitcoin when it was at $3 and now have to justify their pre-held beliefs) have to justify why they didnt think it was possible or "real" even in the face of multiple fusion breakthroughs.