Intel is strategically important. As nice as it is to pretend that the whole world plays by the same rules, that the free market exists everywhere and that we'll never to to war, there are bad actors and the US (rest of the collective West as well) need to ensure that we won't be completely crippled if China attacks a single island off their coast...
That and when most governments "nationalise" corporations they seize them and don't give the owners/shareholders anything.
And it's the standard refrain: if this money helps Intel get back on its feet, the stock price will go up, presumably to the point dilution won't matter.
But who cares, really? If it's true that Intel is actually strategically important to the US, the shareholders are irrelevant if need be. It's not a great outcome, sure, but Intel has been mismanaged for a long time, and investors should have known the risks of investing in a company like that.