One of the problems of scrypt is a lack of language bindings. There's no officially blessed language binding for PHP, there's a ruby gem that only works on MRI but doesn't support jruby. Bcrypt on the other hand is widely supported, simple and easy to use implementations exist for devise and activerecord for example. I'd pick the slightly worse but widely supported algorithm and rather tune the work factor than being stuck with an extension that might or might not be supported depending on the authors availability of time and resources.

This all can change, but that's the current state of things. Sorry scrypt.

I think that since bcrypt is more available I will continue recommending it, and using anything else should be based on a risk assessment. I do not think peoples that don’t do risk assessment on storing password will care enough to spend time on something that is not easy to set up when it “only” affect security