What does "abused technology" mean? The answer is that it means approximately what Amazon and its customers agree it means, as expressed in their contracts. Your personal norms about what abuse is and isn't aren't relevant, because Amazon made theirs clear in their contracts.

Technologists on message boards who are shocked and offended at Amazon's decision are generally tipping their hands that they don't ever have contracts reviewed, or really even think about them in their day-to-day work. A plain reading of Amazon's terms --- not to mention having paid attention to how cloud providers handled Gab --- made it clear that Parler's position was untenable.