Edit: Sorry if this reads preachy. I'm not really Christian but I was born with a Catholic background so I can only reference Christ.
IMO banning competitive upgrade is worse than un-ethical, it's ethics destroying.
Whether that means the existence of the opposite is ethical or not, is up to the person and whether they are the victim and whether they are willing to accept a grand view of things.
At the heart of competitive upgrade is competition. At the heart of ethical competition is to bring forth the best. The exact opposite of what corporations do.
Therefore, it's a lot like the Pharisee questioning whether Jesus being the Son of God and therefore having a higher authority just for being the "Messiah" is ethical.
If you consider and follow a man who will break the Sabbath when it is necessary, would be fundamentalist but not in the dogma of God but in "maximizing" the good will of God, in giving people a choice (discipleship) versus by force (religion) ethical, then yes competitive upgrade is not only ethical it's necessary for just as it may bring forth greater evil (or at least corporations) - that greater evil incentivizes people to form a greater good and greater good means greater chance of progress. Bad for individual business, but great for ethics in the long run.
However real change produces victims. Some who might become martyrs. Martyrs who might become saints. Most who might become unsung heroes and unsung victims. That's not fun at all. Does it lead to greater ethics? Yes.
But not only in business, but in life, we can settle for good ethics. We can go to church. We can attend bible studies. We can make a business selling "inferior" quality and stable products sheltered from the greater evil...and we will be ethical. Possibly socially considered extremely ethical even. Apostles of "Do no Evil" like Google even before we get to become big and amass tons of haters.
So then the true philosophical question is... is protecting the sanctity of good ethics ethical?
Should we let the enemy of greatness, (good) win just to protect ethics?
Not many are willing to ask that question. Worse, not many are willing to live with their answers.
So it happens that the the bourgeois becomes a lie. Not because it cannot be true (in the same way Marxism isn't a lie)
...but it is a lie because it is inorganic. It is a lie because while we may want to "tackle the ethics of our time", we rarely acknowledge the "living ethics" of our humanity.
...and so those that gain that power to answer that question - they too do not have an answer to that ethics. For they realize answering whether it is ethical is also a lie. If they say corporations, people will not accept it is "bourgeois"-like. If they say "bourgeois", they cannot fully encapsulate the cancer of society that is bureaucracy...or what we nowadays know as corporation.
Worse - those in power cannot always educate those who are not and vice versa. The poor will gamble their lives on the lottery, the rich will gamble their lives on stocks and bonds and the bourgeois will gamble on wage slavery if not small business. All creatures structurally similar. Like the unethical hypocritical Jew being similar to the heathen Samaritan and the good Samaritan to the ethical Jew - they are the same BUT they are different!
...and so in the end, the more informed Christians become Atheists and Agnostics. The more ethical developer becomes the unethical trickster. Loki instead of Satan. Summon Bigger Evangelical Open Source Followers instead of Banning Competitive Upgrade. Legislation instead of Futurization. Anonymous vs. Big Brother.
Ethics in the end is not a question of "is this ethical" but rather "my ethics trumps yours".
Welfare trumps Independence. Healthcare trumps Debt. Destruction (or at least the desire to destroy and anarchize) trumps Better Government. That is the ethical answer to this question.
If you can summon angry mobs discrediting your competitor - competitive upgrade is ethical.
If you cannot and are awashed and cannot compete with him and the world turns the other cheek and Lady Luck curses your hard work - competitive upgrade is unethical and life should be given a "normal mode" when things become hard. No, beyond that: evolution is unethical and must be socialized despite the fact that competitive upgrade does not kill you, only make you poor. Poor is bad. How dare someone try to make you poor. How dare the cancer trample the other hard working organs!!!
P.S. I don't really know what I'm saying but this thread makes me want to babble.