Selling the positives for a new programming languages should go hand in hand with a realistic thorough analysis of the negatives.
Negatives of the language as a brief point 18 on the tutorial makes the negatives look hidden.
But, as all good salespeople do, they focus on the positive and leave the negative in the fine print.
Selling happens everywhere all the time without price.
As in nothing functional at all? Or are there anonymous functions etc?