Some engine developers play pretty decently (the Rybka one is an IM, while Houdart used to have many years ago a rating around 2250), but some of them are just class players.
But that was before they programmed the engine, I think he's asking if people have became stronger as a RESULT of making the engine.
I think a better way of view good engine algorithm writes as good at mathematics, as it pertains to chess tactics...
I think I need a translation.
I'll try :p
"It may be that writing a good engine algorithm suggests the person is good at mathematics more than it suggests they're good at chess because chess is mostly tactics."
So it may contain a pun? Both math and tactics are calculated. Honestly not sure though heh.