Are cash buyers always so awful and rude?

Long story short, we debated for some time about selling our fixer upper but ultimately decided to do so and to sell it FSBO. We don’t have to sell it and we’re not looking at taking a lowball offer just to be rid of it even though we’d obviously like to sell sooner rather than later. We worked with a friend who is a realtor to determine the best price, though she is not representing us. The house has good bones but is very dated and definitely is a fixer upper. The barn is small but nice. The shop/garage is in great shape. It all sits on a very nice 5.3 acres with both woods and pasture. We listed the house on Sunday evening and by Monday morning had a viewer asking to see it Monday evening. We showed the house to this viewer last night and they wanted to think about it a day or two. No problem there. This morning (Tuesday) another viewer asked to see if this evening. We’re showing it to him in a few hours. All of that to say, I don’t feel like we’re out of line at all on the price and clearly there’s interest because two viewers in two days feels pretty good to me and we’re the only house for sale in this price range in this school district that is a highly desirable district.

Anyway, this old man has messaged me three times about being a cash buyer, having the money, etc. but refuses to make an offer. He just wants to yammer on about how he doesn’t want to waste my time or his but he’s extremely rude and very demanding. I’ve told him twice that he’s more than welcome to view the house, make an offer, etc. but that’s not good enough. Now he’s messaging again and demanding that I outline for him how I priced the house. He’s extremely condescending, rude, and frankly off-putting. It’s clear that he wants to shoot us a ridiculously lowball offer and thinks we’ll bite. Yes, I’m just venting really, but are cash buyers usually so awful to deal with?