If your wifi is to an internal network firewalled from the internet, then yes of course you'd want to secure it.
But most home wifi (which is what we're talking about here) is routed more or less directly to the inherently untrusted internet. If you're sending unencrypted data you care about to that then you already have a problem. (Yes, it's true that people are sending unencrypted data they care about across the internet and it's true that they already have a problem.)
But most home wifi (which is what we're talking about here) is routed more or less directly to the inherently untrusted internet. If you're sending unencrypted data you care about to that then you already have a problem. (Yes, it's true that people are sending unencrypted data they care about across the internet and it's true that they already have a problem.)