I fully agree with this. Many scientists are very bad communicators, for this or that reason. However, most young people are however very well aware of that and are making a lot of effort in communicating better.
It is also an educational issue. For example, I was shocked to find out that some students here in Germany are already in the second year of their PhD and haven't presented their work publicly (in a conference, for example) even once!
Also, in conferences I've attended there is a very clear tendency: the Americans are usually good, engaging speakers (since their curriculum provides them with more opportunities to learn how to communicate their science, generous travel stipends, teaching requirements, etc), while everyone else is kind of hit-and-miss (lets not even talk about strong accents making the talk unintelligible!).
Also, on different grounds and to come back to the topic, many people just partially ignore data to "prove" somehow "their" theories. Then usually follow ad hominem attacks and so on.
So sad, but so true. Sometimes even when you read the papers, if they cannot hide the evidence or an experiment didn't quite go the way they wanted, in the text description they just pretend that it did (and then you look at the figure and are like, are we looking at the same thing?), haha... I've seen this a few times.
This is really not acceptable. A student should go once a year to an international conference, if money is there of course, and present at least at national workshops.