They know the design laws and rules, and they can (and will) tell you the lineage of a design from the Middle Ages without the slightest provocation. They also work in one of the most vicious of all markets, where plagiarism and creative theft are rampant. Whether they design teapots or trains, the creative issues are all the same.
Creative design is a mix of sweat and inspiration. Having an idea is one thing, turning it into a product design is another. Taking someone else’s design is effectively robbing them of perhaps hundreds of hours of work. This is where ducking the issues, sadly, becomes expedient.
Designers usually have another basic environmental issue which adds to their problems:
Clueless clients who know nothing about the technical issues and less about the design situation. Even when it’s about their own products, they may not understand the significance or values of creative design.
So one teapot looks like another. So what? So everything. A registered design can force an unregistered design off the market. It doesn’t necessarily matter who designed it first, it’s who holds the registration, which is prima facie ownership of the design for statutory purposes.