Ummmmm... because it's hardly a big deal... Certainly not worthy of court action.
Reeks of "I can make some money here".
This really is just another 'only in America' story.

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Or, the user could accept some responsibility, do the tiniest bit of research, solve his/her own problem - and move on.
[Not to absolve Apple of their responsibilities either...]
The reality, is that essentially the only way to follow your advice, would have been for the user to do research in advance, learn that Apple is a monopoly player, and that if they dare to use Apple iPhones, they'll never be able to switch to another phone manufacturer.
There was no amount of information available after purchase to let someone know how to effectively resolve the problem in 100% of cases. The workarounds that were published by others (not Apple) only worked in some situations.
It is Apple's responsibility to undo monopoly practices within their products (regardless of the intention or accidental inclusion of those practices).
Failure to act on the problem, changes it from being an Accidental "Ooops" to being a deliberate action or willful action to utilize the "flaw" to their own benefit (as a monopolist company would do).
Microsoft didn't intend to prevent people from being able to use Netscape. You could use Netscape all you wanted. Yet, their ambition to extend Internet Explorer to enhance the Windows interface led to them being considered a Monopoly using unfair business practices.
The situation with Apple is even more clear cut and much more monopolistic, because they are preventing the switch to a competitor, while Microsoft allowed you to use any competing browser you desired.
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"Moore's lawsuit alleges that she ceased receiving messages after she switched to the Samsung Galaxy S5 from an iPhone 4, which interfered with her contract with Verizon Wireless."
Huh? What does the iMessage issue have anything to do with a Verizon contract? Sounds like someone at Verizon didn't know what they were talking about, as usual...
Or, it could simply be that not every detail was outlined...
It is also possible hypothetically that she was a subcontractor for Verizon, and this interfered with her obligations / abilities to do her job because she didn't get important text messages relating to tasks which needed to be performed.
It is also possible that this simply means that Apple interfered with the delivery of messages to her phone which operated on Verizon. That would interfere with her contract with Verizon, who she was paying to deliver content to her phone, yet Apple intercepted the content and prevented Verizon from being able to fulfill their contract with her.
It's really a simple statement, and people are trying to find some evil in that one little sentence. There is none there. And, it's really the less important detail.