The founders built it using state money as an investment. They definitely fucked up reading the fine print though, and these issues were raised at the time they got the funding:

https://techcrunch.com/2009/10/22/dailymotion-raises-another...

DailyMotion can be a strategic asset for a country like France. E.g. if they project a steep decline of broadcast TV and a YouTube monopoly, having a French-controlled video streaming alternative laying around may become important in the case of a USA-EU "cold war". The chances for this scenario may be very slim, but countries at the level of France would want a contingency plan anyway.

I think that's reaching. That's not just 'slim', that's vanishingly small, so small that such a factor would never make it to consideration in a case such as this. The real truth is that it was the first time that France had a name on a website that had international recognition and they didn't want to lose that.