How is bcrypt more future proof than increasing the number of SHA iterations?

I've been researching bcrypt hashing, and of course one of the large benefits of the scheme its "adaptiveness". However, how is it anymore adaptive than simply increasing the amount of iterations you make over a SHA-1 hash? Say, instead of SHA-1 hashing a value 1000 times, you increase it to 10,000 iterations. Isn't this achieving the same goal? What makes bcrypt more adaptive?