[nullc]

You are right, but there is also a level of reality that needs to be injected: If open source can't be confident of a dismissal these kinds of claims on a summary basis it probably can't exist.

The cost of winning at trial is great enough to be ruinous especially relative to a volunteer effort.

In the case of Bitcoin we're probably better off in the sense that there are wealthy supporters willing to step up and take on costs. But there isn't anything about this that couldn't be applied more broadly to impose far ranging duties on other open source developers.

(FWIW, a fiduciary duty is far broader than just a duty to act in their best interest, it is a duty of single minded loyalty to put their interests over all others, including the fiduciary's own).