My accomplishments of 20 years in somali forums have afforded me an opportunity to contribute to my Somali brethren in a positive enforcement of daily wisdoms and articulate paragraph constructions, which have proved fruitful as I can attest dozen of Somali kids have been influenced by my writings, I could see how they write in my style.
Your innovative use of sentences will no doubt act as a catalyst for a revolution in paragraphs.
In regards to your other points which unfortunately miss the eloquence of your earlier paragraph:
1. SpaceX is wholly private company. They already investing more than any private commercial space company. I'm not sure how much more ambitious than the planned BFR space vehicle you want them to be.
2. High speed trains isn't the market Musk is going after.
The tech can't really be improved that much and most the costs are related to "rights of ways", regulators and land prices.
Going underground would help them avoid most those costs and work on a tech that has plenty of space for improvements.
There's only so much rail tracks you can place over ground.
Underground, you could place thousands of kilometers of tunnels without getting in the way of day to day life above ground.
3. Your cogent argument has convinced me.
4. Try to go after Amazon would end up costing them billions of dollars. Amazon still isn't profitable for a reason. Any competitors would have to face price dumping and losses for at least a decade.