A "loose cannon" is something you own and lose control of.
Musk is not a lose cannon but he is a private individual with his own views and aims which the military do not control, and they don't like that.
If the military wish to have any control they have the option to buy access to the system for a stupid amount of money (that's what the military do) with whatever support it requires. NO military operation (and this is clearly part of a US military policy) should work on the basis of "helping out" as opinions or views on both sides may change.
SpaceX is sailing close to the wind by "voluntarily" taking action to support "freedom of speech" but could be seen by others as the company being at the beck and call of the US military/government, something the US roundly complains about when opposing regimes/companies do the same thing.
Biting the hand that feeds IT
