What turns weakness into catastrophe is monoculture. All software has flaws, all systems have weaknesses, and you design around that by having multiple different systems with different weaknesses. If the world's banana crop is a single strain, then a single pathogen can take out the lot.

You're not going to harden your IT infrastructure by rewriting Active Directory in FORTH under VMS, much as such an exercise may appeal to the more perversely creative. But the more experience you have of seeing things done differently, of analyzing and understanding systems that don't make the current industry standard assumptions, the better you'll be at assessing and working with different contemporary options.