What you are saying is that such business model, where a company creates a computing device, sells the device, and then continue to own the customer funnel for software experiences on top of the device is illegal. If this sets a precedent, and does become the new "interpretation" for anti-monopoly laws, it would also make console business model or Amazon Kindle business model illegal. I could also make the same argument for any kind of "platform" like business. Essentially, when an entity sales one category of products, it cannot use this product's platform effect to control the sale of another category of products. What about leveraging bundling and network effect? For example, Apple Watch only works with iPhone. A person bought Apple Watch a year ago cannot buy a Android phone a year later and have the Apple Watch work as advertised when he/she first bought it. This would also be illegal under this precedent. I think this is a positive thing. But it does invalidate a lot of business model's tech companies are using right now and the higher valuations software/platform companies currently getting. It would also results in fundamental re-calculation of margins and business model for a lot of companies. Might lead to decreased valuations and revenue. This would negatively impact the shareholders, employees and company, who are also stakeholders in this discussion.

And you also cannot look at this law from an ideology perspective, you need to look at the practical affects as well. Going forward, companies will also spent energy to design how their product will interoperate with other products especially those from competitors. For example, if iOS is going to have third party App Stores, it has to be designed in the OS. It cannot be an afterthought. Comparing iOS and Android, you realize when Google built Android it actually has to spent the time and the energy to design the system that enables Android's flexibility and "multiple App Store and install any app package" system. Google has also to spend energy to maintain and support the system every year since Android's release. I know that there are instances where Google want to make changes to Android to better support their own use cases but is not able to because Google has to support these flexibility points. If you look at a from angle of "how much benefit do I get from a fixed amount of effort", flexibility and interoperability becomes significant features. I think a lot of people underestimate just how much effort it is to design, engineer, test and maintain interoperability. From a business perspective, they need to think do I spend the time to engineer and maintain systems to enable interoperability? Or to enable my business use case and enable me to make more money? By changing the law interpretation, the law is making the decision for the business. It's forcing the business to say "hey you have to spend time to build things that might end up benefiting your competitors, and perhaps you don't have time to build this feature that would benefit your bottom line instead ". Not sure where your political spectrum lies, but this definitely doesn't sit well with political conservatism that advocates for less government control over private affairs.

Again, ideally this new interpretation will be good, but I feel there will be a lot of resistance for this "reform" to go forward.

btw, if Apple is going to allow other stores and ISVs to offer users application packages to download and install freely like it is on Windows, any company of significant size is going to start bypass Apple's stores and asking users download Exe's or their own app launchers. Want to play Fortnite, download Epic store and Epic game launcher. Want to use Facebook and play Oculus games? Download Facebook store. Want to use Lightroom, download Adobe CC store. It will change the Apple's user experience, which is part of brand and product proposition. I know some people actually buy Apple because of this user experience. So is it okay for government to dictate such user experience is not allowed anymore? The private entity wants to design this kind of user experience, is it ideologically okay for the government to say "you cannot design a product this way anymore"? Maybe private entity should be able to design a product anyway they see fit, and let the market decide. Look at before there is a market for closed sourced developer tools and software. Now, there is no market for you if you don't open source your developer tools. People rather write apps for open source dbs and frameworks than some companies proprietary stuff. This is an example of market demanding openness and interoperability and making the producers change their behavior.