There could stand to be more thought in many applications put into timeouts and cancellation and how it should all work in the face of APIs that might be unresponsive or slow sometimes. But I don't think that putting some arbitrary timeout as the default everywhere is really a good idea.

Many of these things are used for one-off scripts, where it isn't worth thinking about. For many APIs, it isn't worth the trouble - if one of your dependent services is unresponsive, there isn't really any meaningful thing your application can do anyways. It doesn't become an issue until there are so many timeouts that it's impacting other resources. Best to leave it off until you know what you want to do with it.