Tailwind is a means to an end. If you think writing css is the best way to spend your time, go for it. But I guarantee I can ship things faster using Tailwind.
I’ve learned CSS, used Bootstrap, and tried a bunch of other tools. Tailwind ecosystem is the fast approach to building web UIs in my experience. It doesn’t matter if you know CSS or not. Nobody gains if you know CSS per se. People gain when you deliver finished projects. Tailwind helps ship projects faster.
Who’s to say that person is right? If anything test it. That person may have a personal and incorrect feeling about the logos. They may be worse at b2b sales than you.