Elon "Electric Jesus" Musk only does it as a business model. He'll never do important national stuff that go beyond budget efficiency.
1. This was not a competitively bid launch. Europe provided the budget for launch so they selected their own launch vehicle.
2. Nothing the Ariane 5 did was very special no matter they hype about 'so exact'. Everybody know that was almost certainty happening. It was typical under-promise over deliver. Other certified rockets would have done the same thing.
3. Both SpaceX and ULA could have launched this mission. Both are full certified for first rate, lowest-risk launches by NASA. Please actually go and look at the list of launches and you will see:
SpaceX:
> https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_He...
ULA:
> https://www.ulalaunch.com/missions
4. Both ULA and SpaceX are launching both NASA and Dod payloads. Both required separate very detailed qualification.
5. SpaceX also has launched German Defense sats because it was cheaper then Ariane. Italy has just booked a SpaceX flight as well.
6. The SpaceX Falcon 9 is certified and has launched humans. I would consider that 'important national stuff'.
7. Falcon 9 based on most statistical models is now considered safer then Ariane 5. Falcon 9 has also already launched more often then Ariane 5. Insurance cost of payload on Falcon 9 is also the lowest in the industry.
8. Ariane 5 was just grounded for 6 month because of issues with the fairing and required government intervention. This actually did cause significant concern for James Webb lukeyl they had one launch before to test the new configuration. In typical Arianespace fashion they hid this error for as long as they could and didn't tell anybody why they are grounded. Great security culture they got, always trying to brush their failure under the carpet and not talk about it.
Fine to have pride but don't try to bring others down to lift yourself up. It makes you look silly.
edit:
its payload width*
Since then the price of the rocket has gone from like 20%+ to like 2% or less of the cost. But they will still get the science. So all in all, might be the best investment anybody has ever made in terms of a science project.
The Delta 4, Delta 4H and Atlas 5 would all have been fully qualified to fly the JW and likely could all have launched it. Maybe the Atlas 5 is to small but there were certainty rocket in the US that had the required certification from NASA.
So sending astronauts to the ISS and launching spy satellites isn't "important national stuff"?
Arianespace was the first commercial launch provider.