If they can sell you a mac for $1500 I don't think they are very concerned that you're not spending 50 bucks a year on iCloud.
I mean, if they prevent Linux you probably won't buy a mac at all, you won't prioritise using an M1 macbook over using Linux if you're a hardcore Linux nerd.
Bottomline is that yes they are greedy, but they are not trying to stop people from installing Linux on macs just to perhaps earn some extra dollars.
Counter point: they have no problem charging $1000+ for iPhones and lock them down to only run the operating systems and apps they approve because consumers of them were largely not technical enough to understand they don't own their own devices.
Apple is motivated to do this as soon as they feel they can get away with it and keep profits as high or higher.
I’m not saying they have any moral objections to locking the macs, it just doesn’t make any financial sense. Enough people want to run windows or linux for them to make the effort to make that possible. It’s also more in the spirit of PCs to have this possibility.
For phones, basically nobody wants to run android on an iphone, so it makes no sense to make it possible.
Keep in mind that they don’t lock down iOS because they hate our freedoms, it’s because it is much harder to make it safe and secure if it’s also very open. And since the market of people wanting to run other OSs is so small, they don’t want to take the additional cost.
As to owning you device. Unless you buy real hand stitched shoes with leather soles, your shoes are most likely completely impossible to repair, they’re basically molded rubber. It’s not because Nike hates freedom or even because they want you to buy new shoes more often, it’s because it’s so much cheaper to make shoes that way. But would you argue that you “don’t own your sneakers”?
How do you know the number of people that want this, and how large is the number of 'enough', and what other numbers come in to play? (Number of incidents, number of happy users, number of systems to support, number of binaries to consider during upgrades, number of sales... and is 'enough' a percentage? An absolute number? And how high does it need to be? And to what degree does it need to align with the goals of the product teams?)
My gut feeling would say: a bunch of hackers would be happy if they can hack on their code on Apple hardware but run plain FreeBSD or Linux while doing it. But that is not something you run a multi-billion business on...
My argument is that Apple wouldn’t be losing money by allowing people to install Linux on macs, it’s not about “preventing people from using macs without paying for iCloud”.
But in general, running Windows or Linux on macs is not uncommon, it’s definitely not just for hackers.
I don’t have any numbers at all but I’m sure nobody would doubt that it is orders of magnitude more common than people wanting to run homemade OSs on iphones.
So at one point they could decide that they don't want people to use Linux on their Macs and there's nothing you could do.
Look at what happened to CentOS.