Its more like saying oh well the front door is locked so my house is fine, but the back door is wide open. Oh and also my house is on mars and it is impossible for anyone else to get there.
… until someone builds a space rocket.
It’s like saying "it’s OK, we don’t need to store extra year digits, these computer systems won’t be around when the millennium changes. When wold that ever happen???
Replying on ‘computer can’t currently do it’ always failed to remember that these systems could possibly still be around when computers are more powerful, and might be able to. It’s bad practice to assume it’s safe. Make it safe!