They're valued but aren't predictors of NFL success. Most of the top combine performers haven't gone on to become NFL stars.
There's nuance. First of all to even reach the conversation of being an NFL prospect, you need to have very good speed. For a CB sub 4.6, WR/Safety/RB sub 4.7. Those are at the absolute worst, you'd have to be elite in some other aspect to get considered, and most likely .05 faster is required.
A lot of the combine record 40 guys are very undersized/injury-prone. John Ross has constantly been hurt since being drafted, he's had moments when he's been healthy. Guys like Holliday/Demps couldn't withstand the pounding necessary to be big NFL stars.
For Coach O's purposes, he's talking about at the college level. And there's no question to me that what I said in reference to that is correct. The NFL exposes guys who are smaller, more fragile, unintelligent (DGB), or can only run in straight lines. College you can get away with more of that.