I can't remember exactly how he said it, but it was a short clip from....I wanna say John Jewett...where he said something like a lot of guys lift weights for power and not hypertrophy.
The idea that I took away from it was...you can lift explosively and move a lot of weight, but that explosion is really just creating momentum. It's not necessarily the best thing for hypertrophy.
I don't think that means "do every rep slowly". But I do think it means to be more deliberate.
Probably the same idea that Meth is sharing here but some guys express things in a way that makes more sense to you.
That said, there is science that shows that sometimes explosive movements DO cause more muscle activation and hypertrophy. I saw some nerdy video from Kassem Hanson explaining how this works with Lat Pullsdowns