[WorldMaker]

I think it is definitely a learning curve thing: when teaching/learning Observables it can help to use a name like EventStreams or PushStreams. (An RxJS "competitor" is named XStream for this among other reasons.) Observable is a simple English word and the meaning of the English word is complicatedly "shadowed" by what the tech means by it.

On the other hand, on the other side of the learning curve, Observable is a great name. It's a simple English word that you can say and write a million times (and you will need to when working with them) without extra PascalCase or things like that. Also, when you look at the overall "family" that Observables fit into, it is a name that fits the family: Iterable/AsyncIterable ("PullStreams") versus Observable ("PushStreams"). (In .NET LINQ the family uses Enumerable/AsyncEnumerable and also extends to Queryable and the strangely named but makes sense in context Qbservable. [QueryableObservable; often pronounced like "cube-servable".]) As a family of tools that all generally work well together and are essentially related in a "four quadrant" way, it helps that they all have a nice -able names that sound related.