I'm interested: why not call the raise with A7s preflop?

my reasoning was as follows, I have position, the raise was a small portion of my stack, it is a hand that could improve to the nuts, and I could win a big pot or double up with it if it hits. Original raiser and caller could have pocket pairs or AK-AJ KQ, and I am not playing A7s for high card value.

Thanks,
Mike