If it can be flashed to a Nexus device, can read the SIM and supports the carrier's network type then who cares what the carrier's think or if they pick it up. They aren't stopping me from running Android (proper) or dropping CM or similar after market firmware.

Ok, I get it.. no carrier means no adoption by the majority or are non-savvy or casual users.

For my personal opinion, I latched on to Nokia's N### devices because they where the only upgrade path from the Palm T5 erra devices and because Maemo was about as close to a general purpose OS on a mobile device as one could possibly get (and much closer than anything available now). If Canonical can deliver a "Debian on my phone" experience where I get mobile device GUI/apps with full *nix behind.. oh baby.. Even with the amount of data Android has managed to siphon off into Google's storage servers.. it'll be a hard decision not to go through the grief of migrating my data back out of Google.