Tax payers should not be funding anything like this. Let MS and Google invest in it if they believe in it. It’s gambling with other peoples money.
SpaceX is delivering a service, launching payloads into space, at a competitive price. The government is paying for getting that. The government is not "investing" in SpaceX.
“The Falcon Heavy is an absurdly low-cost heavy lift rocket”
“The bottom line is that the Falcon Heavy is a more powerful rocket than the Delta IV Heavy, and by various measures the latter will probably soon cost the US government about five times as much. Put another way, the Department of Defense may have to pay half a billion dollars more for a single launch of certain military satellites on the Delta IV Heavy versus the Falcon Heavy.”
The actual reality is that the competitors of SpaceX are the ones getting subsidies, by getting awarded contracts when they are not the actual lowest-cost providers.