I fully disagree, how do you think barcodes were invented?
A few uses of Linear Algebra:
Digital image compression
Calculating life expectancy
Modelling population growth
Universal Product Code
If you want a thorough discussion of exactly how they are used, then just open up some linear algebra books, or do a Google search.
Higher math isn't just solving puzzles (In fact, that's not really what math is). People don't just do mathematics to improve their thinking abilities; it certainly helps, but it has many applications.
Keep in mind that mathematics need not be applied to anything. Just because you can't use a result of mathematics (at first) for anything practical does not make it useless.