If we had a policy of nationalizing contracted military infrastructure, then nobody would make a contract with the military.
And while this may sound good to some, it sure wouldn’t be in Ukraine’s interest. Unreliable Starlink access is better than no Starlink access at all.
A key issue, often overlooked, is that US law imposes significant restrictions on the export and sale of military hardware.
Starlink is currently not considered military hardware. SpaceX is desperately trying to keep it that way, their ultimate goal is to sell subscriptions to civilians. Thus they get anxious when it is openly used for military purposes.
In this regard Starlink is somewhat similar to civilian GPS receivers, which automatically shut down at 1200 mph so they can’t be used in missiles.