Blaming the audience makes sense because after all, they're the ones not getting the message right and not asking the presenter to explain it better. But it remains the presenter's failure to catch their attention better and try to deliver a clear message.
Every time I had a presentation, I tried to analyze the failures (including listening to me when it was recorded, a really painful experience). Certain mistakes such as like having slides on a white background that makes attendees look at the screen and read instead of watching the presenter and listening to him can be devastating. Just because attendees are naturally attracted by light. It's not the audience's fault, it's the presenter's fault (and to some extents the tools in use). A good exercise is to stop slides from time to time during the presentation (i.e. switch to a black one), you'll be amazed how much you suddenly catch the attention, you feel like you're at a theater. It even manages to catch attention of those who were looking at their smartphones because the light in the room suddenly changes.
Also another difficulty which is specific to English native speakers is that many of them initially underestimate the difficulties of the audience to catch certain expressions (with some people it's very hard to distinguish "can" from "can't" for example, which complicates the understanding), or idiomatic ones, or references to local culture, because such things are part of their daily vocabulary. Of course, after a few public talk, when they get questions at the end proving there were misunderstandings, they realize that speaking slower, articulating a bit more and avoiding such references does help with non-native listeners. Conversely, when you present in a language that is not yours, you stick to very simple vocabulary using longer sentences to assemble words that try to form a non-ambiguous meaning. It can probably sound boring for native speakers but the message probably reaches the audience better.
In any case, it definitely always is the presenter's failure when a message is poorly delivered and their responsibility to try to improve this, however difficult this is. It's just important never to give up.