Just to clear a few things up:
There's no reason to hide a quilt when company is coming. You need to ask a designer's permission for public display only. The article in question makes this distinction very clear.
If someone wants to make a copy of a quilt that you made based on a pattern, it's not a problem. That person just needs to buy their own copy of that pattern, which in this day and age of the internet, is very easy to do. You can often get out of print patterns very easily as well, sometimes for free, by contacting the original designer.
Designing a quilt pattern is no different from writing a novel when it comes to copyright. Novelists all use the same tools to make their stories. Quilters all use the same tools to make quilts. When you come up with your own idea for how to put those tools (whether they be words or blocks) together, it is copyrighted, period.