This couldn't be further from the truth.
My husband's job requires a Top Secret Level Clearance from the government, as do many other military, federal government, and contracting jobs. A major part of being able to obtain and maintain that Clearance is having a good credit score. They will literally revoke or simply refuse to issue clearances for poor credit scores or even if your score starts going down because of late or missed payments. This is a serious issue and can mean you are suddenly no longer employable.
Many other jobs use credit scores to screen potential employees, and as mentioned, it's absolutely a requirement to secure many kinds of housing, especially rental housing (private or corporate rentals).
Credit scores are even used when establishing utility accounts, cell phone plans, etc. People with low scores often have to pay large cash deposits when opening up these accounts.
The people who think credit doesn't matter are paying more for everything they do.