In bridge, can "good" players get away with bidding "light"?
"It takes 26 points to make a game" is clearly a rule of thumb, not a hard rule.  Anyone who has played more than a few hands of Bridge should be able to see that, sometimes, light hands combined with intelligent play make a contract; and, sometimes, a solid point count is brought down by a bad lie of cards or a clever defence.

I don't think any of this is at all controversial.  An expert is going to be able to read his/her hand for more than just a bare point count.  As you say, JT9 is worth more "points", in the right circumstances, than J32, though an absolute beginner may not yet understand why.  An expert is more likely to have the confidence to relish the challenge of trying to win out with a borderline hand.  An expert is more likely to have the arrogance to assume he/she can outplay the opponents, even from a seemingly unfavourable position.  If the expert bids correctly, the opponents may not even realise the cards and the points actually favour them, until it's too late!

I'd definitely worry slightly about a partner who is "surprised" by 24 HCP making a 3NT contract, I have to say!  It seems like they must still be missing something crucial in their understanding of what causes a Bridge round to be won or lost...