Those regulations are written in blood. Thousands of airline passengers died to get those regulations where they are today, and lessening them would likely cause more deaths.

I see this entirely differently -- the FAA was being way too lenient/cozy with Boeing, and took their word that the airplane operated exactly the same (even if it didn't). This to me indicates that harsher regulations are needed, not less harsh ones! In what other industry do manufacturers self-certify such safety-critical machines?!

Relax regulations and we'll just start seeing more of those crashes that have killed so many airline passengers previously. It's a proven fact across all industries since time immemorial; companies don't make things safe out of the good of their hearts, and are OK with shockingly high body counts. Governments have routinely needed to rein in companies that were playing fast and loose with safety.