I think there are two (perhaps more) aspects to writing good
documentation and accepting / making contributions:

1. The basics -- write a paragraph or two describing some feature.
Orthogonal to that and here is where each format bites in different
ways:

2. Integrating that contribution into the main corpus of the work --- at
   the write place, with the right surrounding context, generating the
   right table-of-contents and menus (a running nightmare in Texinfo if
   you dont set things up right at the beginning) and so on.

I think (2) might likely contribute negatively to  (1) happening more
often.

So rather than arguing about formats (and it's been pointed out already
that there are tools for automatic conversion) we should perhaps:

A. Create a simple content repository where contributors can check-in
   their small to medium contributions in the format of their choice
   (limited to a few open formats) along with the meta-data 
B. A small group of more experienced volunteers take on the task of
   incorporating those contributions into the main work.


-- 

Thanks,

--Raman(I Search, I Find, I Misplace, I Research)
♈ Id: kg:/m/0285kf1  🦮