I don't use earphones on my phone that much, so non-wired earbuds would either be on their charger and inaccessible outside the house, or in my bag but out of battery because I forgot about them last time I came back. I can put wired earbuds in my pack and forget about them for months and they still work when I pick them up.

Also, I refuse to deal with Bluetooth until pairing reliably works and sound is always high quality even with microwave interference. I don't expect them to succeed.