1/4" cables are more standard, you and I have more of them in our spares drawer. We can use them for MIDI, great.
Listen, I'd love it if MIDI was used properly with 5+ pins, differential signals over twisted pair, proper power delivery, etc. But they don't get used that way, and so the special connector and cable are stupid. You need three conductors, 1/4" TRS is standard.
Again, we live in a mixed MIDI jack world already. You're going to be annoyed with whatever the solution is, whether it's a special TRS->DIN cable or a MIDI hub. But since you're annoyed already, at least with a MIDI hub, one more 1/4" MIDI isn't going to add to the annoyance.
Partly sarcastic. Partly I think consumers care, and therefore pedal companies care, therefore DI should care it's 1/4".