Do you think that Elon should have unilateral, unchecked ability to export military weapons communications systems? Even to Ukraine? I expect the answer to that is no, for you and most people.
But all SpaceX has done is enforce the terms of Starlink licensing. Terms that were there from the beginning that disallowed them from using it for weapons, and ones that are required by ITAR.
Ukrainians are of course very clever and are fighting for their country, and found workarounds to the limits that SpaceX put in. SpaceX then found how to block those. I don't begrudge the Ukrainians this, but at the same time SpaceX cannot allow their civilian network to be used for military purposes. It would be blatantly illegal for SpaceX not to block these uses when possible.
If you think Elon should not be allowed to make these decisions, then you should support precisely what they've done: unconditionally disallow any non-civilian use of Starlink. The military can use Starshield, which is under control of the military and for which the commander in chief decides the rules.