An open source product cannot be EOL'ed if its community wants to keep using it.
Sure its leading lights can lose interest or disappear, in which case new drivers or a fork will evolve if the community wants it. If the community can't maintain itself then the product drifts off to sleep and there is nobody for people to blame but themselves. Seems very wholesome to me.
As for the demise of VFP: sheesh. At least GM didn't try to blame loss of market interest for its decision to terminate Oldsmobile. For years Olds was regarded as the brand that carried much of the technical innovation in the market. Then GM hemmed it in, assisted internal competitors and poached its good people, eventually terminating it for their own benefit to rationalize their products. Even then there were people wanting to buy the brand and the plant to keep making cars. ;-)
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1