You don't need to convince them of the need for good design, you need to convince them that what they're doing now isn't good design, and that they should do so

You don't need to convince them of the need for good design, you need to convince them that what they're doing now isn't good design, and that they should do something different. I'm saying, citing the project they think is an example of bad design isn't going to help, your opinion will carry less weight.