Why has Hobo not been absorbed into core Rails?

[Michael Q]

I'm baffled. Why is this great tool Hobo not more generally adopted by the Rails community? For example I would have thought that the Migration Generator should be a no-brainer for adoption into core Rails. If it were more widely adopted, the lag in its development and documentation would likely be reduced by greater community involvement

Could it be that the wider community doesn't know about it? Or are there hidden disadvantages to using Hobo?

.Michael