"No company in their right-mind is going to spend billions
on ambitious, expensive, risky projects that have a high-probability of frequent-failure, low-profit returns and a development time-span
lasting years, if not decades. "

And govt in right mind should not do this.

"Private corporations like Northrop, Boeing, Convair & Lockheed have made rockets over 50 years BECAUSE the US Government bodies/agencies [like NASA, Pentagon] have provided the the billions in dollars those companies were NOT willing to invest themselves out of their own pockets."

That should tell you something.

"Speaking about the bidding/contractual process for building space hardware?...
Isn't it to the LOWEST BIDDER?
That means the company that has the lowest bid gets to build the hardware.
And how is that company with the LOWEST BID going to make money
[a healthy profit] on that hardware it got the contract to make?
That's a puzzle.
Does 'cutting corners', speeding-up the manufacturing process, tinkering with the quality-control process, elliminating safety measures on the hardware and its manufacture explain that puzzle?"

Not really.
Bidding on a contract (determining price) is a complicated process.
Evaluting which bid you should accept is also [generally speaking] a complicated process.
Then there are other factors involved besides this- particularly in govt contracts and also in large businesses- and these other aspects can easily "trump" the "plain" bidding/contractual process. You can characterize this aspect generally under the term: lobbying.
As I said determining price is complicated. But anything complicated can "easily" be made even more complicated. This can be accomplished, by simply have fools involved, and/or if the process been made vastly more complicated then lobbying becomes a more deciding factor.