I agree. Many companies, including mine, run critical stuff on applications that are over a decade old that do just fine. Worst thing you can say about them is that some weren't designed well enough for easy extensions or integration with newer apps. They do their job, though. The backbone of ours is mainframe code running on mainframes and AS/400's with simple, terminal interfaces. Terminal stuff is ultra-fast & reliable but sometimes ugly. Some have GUI apps that basically hide the terminal details they interact with to be a bit easier to use. Those terminal apps, probably 20+ years old, still work and get periodically updated. New people learn them easily, too, since interface was well-designed for the time. Can't goof off on the thin clients either as there's no web browser or native apps. ;)
I've seen Google do some rewrites that make sense when one has the money for them. The shift from eventual to stronger consistency in their databases via F1 RDBMS was impressive. Worth some rewrites across the apps to use it to knock out major problems that could affect them once and for all. After developing Go, they also might want to rewrite performance-critical apps in, say, Python to it. There's definitely benefits on such rewrites. A lot of the other stuff I'm betting they could've done more long-term esp if using and extending FOSS solutions.
I've seen Google do some rewrites that make sense when one has the money for them. The shift from eventual to stronger consistency in their databases via F1 RDBMS was impressive. Worth some rewrites across the apps to use it to knock out major problems that could affect them once and for all. After developing Go, they also might want to rewrite performance-critical apps in, say, Python to it. There's definitely benefits on such rewrites. A lot of the other stuff I'm betting they could've done more long-term esp if using and extending FOSS solutions.