I agree, but it's actually hard not to nerf scrypt, since it's time-cost and memory-cost are tied together. I'm not sure if they could have increased the memory cost sufficiently for their purposes, without making the time cost prohibitively high.

That's one of the things argon2 (https://github.com/P-H-C/phc-winner-argon2) is trying to fix, though I don't think any cryptocurrencies are using it yet (which is reasonable, it's just too young)