I think the author is rather saying that anti-personas are people you DO NOT WANT to sell to, not ones you just have a hard time with. For instance, if I am a

I think the author is rather saying that anti-personas are people you DO NOT WANT to sell to, not ones you just have a hard time with. For instance, if I am a B2B product that really requires a large-scale (say, 10,000+ endpoints) deployment to really become valuable to a customer, I really should try to avoid selling to a 300-endpoint small business. And I sure as hell don't want to sell it to some random grandma who's not even running a business. I won't flat-out refuse, but it's not going to help me or them to give them a product that is mostly useless to them. It hurts them because it's a waste. It hurts me because now I'm either setting up a future disappointment, or I'm potentially going to expand my product scope/features to try to become useful to this new group. A product can't be everything to everyone, and just as it's important to understand what your product will do, and who it will be for, it's important to understand what you refuse to let it ever grow into doing, and who should not consume it as a result.