If you have rodents inside your walls or attic, you have a major issue unrelated to the PEX. Also, to my knowledge, the colored PEX is the main culprit. Clear variants aren’t nearly as “tasty”.
Either way, if you have rodents inside… that’s its own issue.
Do you argue against layered security in your day job? I'm making a case for reducing blast radius in the event of a breach.
Of course rodent issues are related to PEX: now if a rodent ever does get in, the damage is multiplied when they eat your delicious PEX water pipes and you get a flood in addition to all the other horrors. Not so with metal piping.
It would be nice if all homes on earth could be completely 100% rodent proof forever. And it would be nice if attackers never breached computer systems. But some of us have to live in a world where such things happen.
You’re over prioritizing an edge case while ignoring benefits, I’d say.
If you want to talk about blast radius: PEX is substantially more resistant to freeze bursting. What about houses that are poorly insulated, so they are prone to pipe freezes? Copper pipes would be ill advised in that situation. I assume the same houses that are prone to rodent infestations are also poorly insulated. Which is more likely to happen I suppose depends on your climate.
Maybe I'll run it by my homeowner friend who suffered through the rat-chewed-PEX flooding that a PEX booster I came across considers her experience an "edge case". If I want to see her cry tears of blood, that is.
For good measure, I might also remind her that notwithstanding the flooding, the rats were a "major issue". Just in case she was confused about that!
Either way, if you have rodents inside… that’s its own issue.