blackjack doubling soft hands A,7

[nowhammies]

What's the point of doubling A,7 if you should stand if it's not permitted? If hitting it isn't a good idea, why would doubling it be better?

I'm not sure why doubling soft A,x in general is beneficial to the player since it removes the player's option to take more cards and even the main dealer bust cards, 4,5 and 6, have only about a 40% chance of busting. My guess is the expected value on computer simulations is positive.