I can understand why you find this idea appealing, but consider the
drawbacks of implementing this kind of system in a *security-focused* OS
project:
The vast majority of donors have much less security and technical
expertise than the Qubes team. Therefore, well-intentioned donors who
vote for certain features may be unwittingly working against their own
interests simply because they do not realize the security implications
of some feature they *think* they want. Likewise, they may be
unwittingly working against their own interests in "down-voting"
(de-prioritizing by not directing donations toward) some feature which
they think they don't care about but which would actually be much more
important to improving their security.
This system would effectively shift the direction of the Qubes project
from the team's judgement to the voters' judgement. In other words,
instead of the decisions being made by the Qubes team, the decisions
would be made by those who donate the most.
***
This FAQ entry (from
http://qubes-os.org/trac/wiki/Donations) is also
relevant:
Q: I have donated X number of bitcoins, can I request a special feature
to be implemented?
A: The simple answer is: no. If everybody was to decide, then we would
get nothing implemented. However, if you make a substantial donation
(e.g. such that you believe could be used to pay for several months of
work of a developer), then please contact us in person or via the
mailing list. You can attach a digitally signed message using the
bitcoin address you used for donation in order to proof that you indeed
made the specific donation. In that case we will listen carefully, and,
in the worst case, explain to you why we can't or don't want to
implement your requested feature.