That isn't due to a missing timeout, that is due to not properly communicating aborted requests down the stack which, admittedly, isn't always easy and some clients/languages/etc. are very bad at. A hardcoded timeout, while a fine workaround in some applications, is not a good default and not the proper fix for that.
Default timeouts in the database layers are hidden time bombs that turn operations that just legitimately take a bit longer than some value the library author set that you didn't even know existed into failures that get retried over and over causing even more load than just doing the thing once. Don't get me wrong there are lots of uses for setting strict timeouts and being able to do so is very important, but as a default no thanks.