Going alone is fine if you are patient and only go out alone when the conditions are excellent. No more dangerous than MTBing alone, open-water swimming alone or anything else where not having someone to hand could reduce your chances of surviving. There’s no-one around to impress/distract/affect judgement and all your mental and physical energy goes into skiing the best line cleanly.
I only know one person who has died alone in the mountains and several who have died in pairs or in groups in places their better judgement would have probably told them not to be had they been alone. Fear is a good thing, peer pressure is not.
I don’t disagree with you. In fact, I regularly go out alone in the mountains in all seasons. I like the solitude and the self-sufficiency of it.
Nevertheless, backcountry skiing/snowboarding solo is a risky game that should really only be played in very, very safe avalanche conditions. Even then, choosing lines very carefully to avoid risk. I have many years experience to help me make those decisions, but, with all due respect to michaelmcc (who I know is training as an instructor), most people asking about backcountry ski routes on a mountain-bike forum would be unlikely to have the experience required.
Some lines I actually think are less risky solo – tight couloirs, lines with exposure, etc. I don’t really want to be thinking about anyone else in those situations.