No it isn't. It's to force you to use credit under the guise of checking how good you would be at paying back.
I'm from europe, you know how much credit i had before i got a loan for my condo? absolutely zero. All they needed to know was that i had no debts, lived well within my means, knew what i was doing, not "how many credit cards and car loans have you got running". The best possible person to loan money to is someone with 0 credit history who can prove they've got a solid source of income, and are living well within their means. Because you know, once i bought my condo, paying my loan is the exact same thing as paying my rent.
And if you wonder if i got a decent loan with such a "terrible credit history". It was a loan with variable interest rate, after the first change, my interest dropped to 0 due to the financial crisis, and it remained at 0 until i paid it of.
Anyone actually believing the american credit score system is anything else than just a way to force you to use credit while you really shouldn't, is just indoctrinated. I'm sorry, but someone perfectly paying rent, and saving up for purchasing a house without ever using any credit is the perfect person to give a good mortgage too, and the exact kind of person this system sets out to punish because they're not taking part in the American banking system the way the banks want you to.
Someone else already replied, but about living within your means, lenders can look up other debts you have, and missed payments you have. And they all request access to your pay slips so they get a basic view of your income. In the end it's close to the credit score system, with the difference that someone who doesn't have any loans or credit cards willl also have a good score since they don't have any missing payments, and haven't gathered too much debt already, which makes sense.
Regarding your point of rent vs ownership. In the end you can still boil it down to needing a certain amount of money/month. Only part of it is your mortgage of course, you need to save up for bigger things, but it's not that different. And i don't even see this being relevant in this discussion, i don't see how the credit score system would predict you being up to being a house owner and setting money aside for bigger repairs.