That's a bad argument.

Let's say that you wanted to advertise on the top of powrelay.xyz/explore then you would need to add pow to your ad. It doesn't matter that mining Bitcoin is a better use of pow, you need the pow to post. So you will do the pow, but only if the value you get from the ad is greater than the Bitcoin you could make by mining.

(this is hypothetical, a Bitcoin asic cannot mine nostr pow)