I would agree with this analysis in the sense that you are adding nothing of value and that it may be somewhat immoral. However I would disagree that CC churners increase costs to other consumers. In theory CC companies aim to set their fees at the point that maximizes profit, they don't just up their fees a little to make up for the rewards handed out to churners.
In other words, their fees/rates are set to a point that gives them the best returns. CC churners take a little chunk of that profit that has already been set by the market. Admittedly, this equation may be more complicated than theory can explain but this is my best understanding of it.
I think it is helpful to first look at the concept of credit cards holistically.
To the best of my understanding, here are all the parties involved:
The Merchantex. Wal Mart
What they giveMerchant transaction fees, payable to the card issuer and the credit card company.
What they getA general increase in the the volume and the ease of commerce.
A competitive advantage over merchants that do that accept credit cards.
The Credit Card CompanyWhat they giveThe infrastructure through which transactions are processed.
What they getPart of the merchant fee.
Fees from the card issuing bank, and the merchant's bank.
Data that can be anonymized and sold to marketers.
Card Issuer/BankWhat they giveTaking on default risk.
Fraud/purchase protection for the consumer.
What they getMerchant fees.
Interest payments.
Ability to market more products and services to cardholders.
CardholderWhat they giveCard membership fees.
Interest payments.
Personal data.
What they getPurchase protection.
Ability to buy without cash.
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The above is a pretty clear win-win-win-win from my perspective. If we accept that, we can think about intro offers and card perks much more clearly. Instead of looking at it as one part of an extremely complex web, we can look at is as another feature of something we already accept as above board.
At this point, when a card issuer offers intro bonus points, it is basically a marketing expense. Chase is paying money to get more transactions, more cardholders, and more data into their ecosystem. They can't collect merchant fees on transactions that don't run through their card. They can't (easily) market more services to a consumer that they haven't established a relationship with.
Is the amount of business I generate for Chase worth the bonus offers I collect, given that I never pay them interest? That is probably unknowable. On the one side, we would stack up all of the bonus points I've earned. On the other side, we'd stack up all the card fees I've paid, merchant transactions fees I've generated, travel agent fees I've generated for Chase by booking through Ultimate Rewards, a fraction of the account activity generated by those who have used my referral code, etc.