The first sentence of this post is clearly stating there are obvious reasons to avoid credit cards because there most certainly wrong ways of using credit cards.

The first sentence is implying that the poster knows there are wrong ways to use credit cards, but that this isn't what this post is about. This post is about the RIGHT way to use credit cards, which there is a right way to use (using them for purchases you can afford and would have bought with cash regardless and paying your bill, in full, at the end of every month). The OG poster reiterated this here: https://board.okayplayer.com/okp.php?az=show_topic&forum=4&topic_id=13345646&mesg_id=13345646&page=#13347489

The first sentence is there to keep people such as yourself who want to preach "STAY AWAY FROM CREDIT CARDS!!!!" because the people in this post want to have a discussion about what credit cards to use because the assumption is the people in this post already know how to use credit cards the right way and are using them as such.

There is no sensible reason to not use cash-back credit cards for every day purchases (again, we've already established this is a discussion for people who use credit cards THE RIGHT WAY which I do not feel I have to define once again but since you obviously aren't getting it I will, the right way being using them for purchases you can afford and would have bought with cash regardless and paying your bill, in full, at the end of every month) because if you do not you are just leaving money on the table. You are literally losing money by paying with cash instead of getting 1-5% back. I've earned nearly $3,000 by using my credit card instead of paying in cash in the last 7.5 years.