Electrical Engineering & Electronics Design

This question always baffles me. The electronics and circuit design engineering inside some of the latest electronics test equipment is clearly incredible engineering and is usually reflected by the astronomical price. However when it comes to their design engineering departments making their latest enclosure designs they are still using bromine wait a year and I will turn yellow plastic and using an enclosure design that would not look out of place in the 70's or 80's. What is going on, It is like designing the latest state of the art engine technology and then putting it in a 1970's Robin Reliant to promote it. I have seen more modern design engineering and materials used in everything from children's toys to kitchen appliances through to cars to aircraft so why is electronics test equipment so behind the times when it come to enclosure design. What are your thoughts on this ?