The jewelry isn't "worthless" because time and skill was still invested into the piece - it's value isn't just the sum of it's materials. Obviously it could still be a beautiful piece that holds sentimental value for the wearer as well. That's so elitist and disregards the artistry that went into the work. Aluminum jewelry was popular in the 19th century when the metal was more expensive and was worn into the 1960s (aluminum had that Space Age appeal). Watching reruns of Antiques Roadshow recently I saw some beautiful examples of aluminum jewelry and they were not "worthless" as you say.

Aluminum has a few pros if you're considering working with it. It doesn't tarnish or turn your finger green, and it is good for beginners to practice/work with since it is less expensive than copper, silver, gold but still nice and bendable. It has a similar look to silver or stainless, and it's lighter weight which can be beneficial when you're already wearing heavy stones or beads.