Declined business credit card questions

I tried applying to a business card to pay my taxes but ended up getting denied for it. I was surprised because I've never applied for business cards before. One of the decision factors for being declined surprised me because most of the DP I've seen seem to suggest this information wouldn't have mattered:

Based on your credit report from one or more of the agencies on the back of this letter, there are too many active credit cards based on your loan history and legal entity revenue

I put a low revenue because my "business" is me presumably beginning a tech startup in the bay area. There would be some small monthly spend to start but no revenue. I've seen many posts say they put low numbers here without issue. I at least put an estimated annual revenue that was slightly higher than 12x my monthly spend estimate as I assume I will be able to get a few personal friends to "be the first customers'.

It's worth noting I also checked Amex Business Plat and got the popup-jail saying I'm not eligible for the offer. I found this odd because I know I'm eligible for non-business Plat SUB.

Is this normal or expected? Did I fail to do appropriate research before proceeding and miss data points somehow?