Reasonable, but that means you're not only leaving money on the table (in the form of credit card rewards or cash back), but also you're not taking advantage of a great benefit: credit cards give you a firewall between merchants and your actual money.
If a merchant fraudulently -- or even accidentally -- debits your bank account, then that money is gone. In many cases you will be able to get it back, but how long will that take? Days? Weeks? More? If the bad transaction is large enough, maybe you won't make your rent/mortgage payment that month. But with a credit card, the money is still in your bank account, and you can dispute the charge, and have it removed before you've spent your own money on it.
Yes, credit cards do require some discipline. I pay mine off every month, and incur no interest charges, but sure, there's the possibility that I could charge enough in a month such that I wouldn't have the cash in my checking account to cover it at the end of the month. I generally don't consider this an issue, though, as I don't have a compulsive spending problem, and I track my purchases well enough in any case.
In this day and age of incredibly poor customer service, I think it's invaluable to have some intermediary fronting the money for my purchases, in a way that lets me dispute transactions I think are in error before having to spend my own money on them.