This means that legacy has to continue to be maintained for security issues. See Rails 2.3 (http://www.kalzumeus.com/2013/06/17/if-your-business-uses-ra...)
Even automotive manufacturers have to supply parts for cars they manufactured for X number of years after the final production. I hope new 2014 cars don't include parts from the 1940's era for "compatability" reasons.
No 1940s vehicles didn't come with ABS, front and side panel air bags. But linkage in the suspension was at least metal, and wasn't known to fatigue every five years. If I were so inclined I could bring my hick mechanic in here and he would have volumes of corner cuts to cite that have resulted in unnecessary deaths over the years.
Some advancements have been great but overall legacy parts don't engulf vehicles in flames. Hodge-podge workarounds do[1].