IMO the problem of many platforms is that they don't let you "own" the software (whatever that means).
Steam experience is closer to the feel of ownership because: - Most games don't just randomly upgrade. They are stable. - Steam is cross platform enough that you can use the software on different devices as if you were copying it. - Your steam account isn't the center of your digital life, it's access isn't subject to many associated risks.
The accumulated loss, if some people lost their access to Steam is huge though. For some people that's thousands of euros.
I don’t buy that justification, most people have never and will never spare a thought for “software ownership”. I’d bet the truth is closer to “people don’t see games as software, but as entertainment. Paying for them is no different to paying to go to the movies, buy a song on iTunes, use Spotify, or Netflix”.
Apps (“software”) and games are fundamentally different in the public’s perception. Look at the App Store, it has two different tabs for games and Apple is even making a separate app for them.