Well maybe you have a period, but this can be changed (other engine)
Who the fuck's gonna change engines when you have assets being done?
Really all models are done and all needed to do now is export the final version tomorrow and release beta next week? Nonsense.
At this stage it should be trivial to have same model used in other engine.
Modern engines should support same formats, and exporting it probably least worry of the 3d artists.
It's the reason why even amateur kids exported models between Q1,Q2,Q3, Doom and so on, changing engines.
Can your brain comprehend that open source often makes shitloads of money?
Give an example.
Open source mozilla/firefox gets millions, e.g.
56,000,000 $ in year 2006 from Google (biggest sponsor) alone.
Linux Android is most popular operating system on smartphones and is even better founded for sure
Btw.:
Not even the orginal desighners of the engine deemed linux a worthy audience.
And Nokia didn't considered Linux a good OS for phone after 2010 and they chosen loldows 8 phone.
Btw this decision seems to be main reason why nokia circles the drain next to Blackberry/RMI.
Linux mobile (as openmoko) was not a success but just 2 years later Android sure is.
Maybe it will happen to world of gaming too, maybe not, but you can not use this logic of yours to say it will definitely not happen.