Generally, in such cases, he may be right / wrong. It doesn't really matter if you ask me. The way I see it he already has a successful business. He doesn't need to pick on stripe / YC.

Building a successful business is difficult. A great idea / execution / being resilient will always get you a good share of the pie. That's the beauty of free market. Just because 1 or 2 people don't like you doesn't mean the whole world doesn't like you.

I think the author is making Stripe / YC much larger / bigger than it is.

If the author is reading this. Just focus on building and shipping the best product. Everything else will work itself out.