There has always been a place in the field of graphic design for trendy design and original thinking. It's been going on forever. The public thought Art Nouveau and Art Deco was decadent and overly sensual. German Plakatstil was considered ridiculous, but they established a style that informed Art Deco advertising. Paul Rand was considered a radical for his use of geometric iconography. Back in the day Tomi Ungerer, Saul Bellow, Milton Glaser, PeterMax, etc. were producing work that expressed a liberal sensibility that flew in the face of conservative sensibilities. David Carson tore up type in the eighties, and artists such as Gary Panter and Art Spiegelman defied convention before the onslaught of computer aided design. Stefen Sagmeister and Paula Scher were spearheading radical design thinking in the 90's and into the 2000's. It continues today as the means of production have become more democratized and anybody with a computer can experiment with type and imagery to create whole new design languages.
The work of the sign maker has changed as the consumer interface has changed. Today we tend to sell lifestyles rather than products, and the consumer is more likely to go online to buy something. Brick and mortar stores are less relevant, and branding and cultural identification reign supreme. What is lost, however, then and now, is clarity and direction. The bulk of good design still relies on legibility and clear communication. Often the message is obfuscated by style, and the basic job of the design does not get done.
Most of the shops that work with trendy concepts fizzle out after the trend becomes passe. They are following trends rather than being innovators. Most of these designers are not on a par with Paul Rand or Paula Scher, and will either keep up with the times or become irrelevant. In the sign business it's probably a good idea to be aware of trends, but to design to the critical needs of the client, eschewing fashion for pragmatism. I think it is a dubious proposition to offer flashy graphics, but not even be able to produce a legible sign for their own shop. I wish these people well, and I admire their hutzpah, but they would be well advised to spend some time considering the nuts and bolts needs of the client. If you can't read the sign, then it is not working, and despite how hip it is, it has no value to the client.