I have no job, no income, and I'm broke.  My credit is therefore way down.  When I HAD employment I tried to keep up with all of my bills, and maintained a pretty good credit rating.  Having a bad credit rating, these days, actually makes it harder to get a job, harder to get a place to live, etc.  How could I possibly build up BT credit?  Or reputation, if you are talking about a trust system, like Web of Trust.  I was given 0.5 BTC way back when I first started on my own BTC journey.  Since then I've received and spent a total of 8 BTC, or something, even though at any given point I rarely had more than 1 BTC in my wallet.  Does that mean I've built up some trust?  I dunno.  Could I borrow and pay back a bitcoin?  Then borrow and payback two?  Then three, etc.?  Incrementally working my way up?

If someone gave me enough BTC to purchase and run my own mining rig, I'd be able to Earn BTC and pay a monthly amount till I finally pay off the loan.  And I'd do that, and not skip off with the BTC, because the incentive of being Trusted for higher and higher loan amounts is far better than the horrible feeling I'd have from stealing all those bitcoins and losing all the trust I'd built up over time.