Re: If we self-ban any vendors who do this shit...
"We'll run out of vendors to buy from."
Agreed. Knee-jerk reactions are often unjust, and rarely adequate.
Main thing to understand would be that corporations and their brands are not monolithic entities. There are several divisions, essentially different companies, whose goals are often in conflict. For example, Sony Music (aka former Columbia) is a very different beast than Sony Electronics or Sony Mobile. Punishing other divisions for that bloody rootkit is an overreach.
On the other hand, misbehaving division is not good for the company, nor anybody else. So there is a reason to make noise about it, in a hope that the corporate overlords can be persuaded to take actions. Hasn't happened with Sony conglomerate though. They're still stubbornly subsidizing their failing entertainment arms. Maybe they do deserve the ridicule afterall.
Speaking of Lenovo - they're not a single brand either. Consumer division seems to live on a different planet. Probably have green skin and tentacles too. Business side seems to have its own share of morons - somebody thought it's a good idea to introduce "affordable Thinkpads" like S, L and Edge series. Which are nothing like Thinkpads if you'll have a look under covers. Cheap noname stuff with a Thinkpad logo. Classic example of brand dilution. And even IT guys often fall for this scam.
Fortunately, T, X and W lines are still worthy.