Also, I'd much rather plug things into my router, which has ingress filters, than my modem.
Inclines me to believe that you haven't been burnt, yet. If your WiFi setup works stick with it until the day you die, possibly pass it on to your descendants - they'll appreciate it.
Exaggeration aside: WiFi has to be the most horrifically inconsistent technology that we have. A friend's setup will spontaneously hit 200ms latency, which can only be repaired with a restart of the device. Other friends have lesser horror stories to tell, but most people I know do have them.
I only use WiFi when I don't care about the quality of the internet connection. In truth: my setup is probably excellent but I simply no longer trust the technology at all and I suspect that many of the people complaining about the ethernet port are in the same boat.