You already have the answer:
On one side, you say you need millions to do it, on the other side you want a bunch of TMOers to do it by themselves on their free time.
Every big OSS project that succeed was backed by a company (Red Hat, SUN, Trolltech/Nokia/Digia, ...).
If that backing company is not Sailfish, you have to find another one.

Or maybe the missing part is less work than I think and 10 people can do it in their free time ?

And about the consistency : it is hugely needed as it is directly correlated to usability.
We have seen a lot of inconsistent interfaces, and they are a pain to use (Windows 8, Android, ...), compared to the consistent ones (Gnome, Meego, Sailfish), even if at the end you can do your tasks on both.