Not only that, but I think the "average user" probably has lesser taste than the tweeter. They see a blue font on the text they are copying from some random web

Not only that, but I think the "average user" probably has lesser taste than the tweeter. They see a blue font on the text they are copying from some random web page, they expect a blue font when they paste it. This would be especially important to the average user if they are copying a lot of text with bullets and headers. So the tweet may be describing a better practice for many use cases, but it may not be the practice most people want.