It's VERY irritating.
I do a fair amount of content editing and creation. And one thing that I have learned is that very smart people like to use a lot of words. A lot of very BIG words.
This was amusingly demonstrated in "How I Hacked Online Dating," a TED Talk by Amy Webb. Amy found out that like her many highly educated and intelligent peers, her profile on an online dating site was 4,000 words long. No one was reading it. In fact, by analyzing the most effective profiles, she learned that the most read ones were at most 100 words long.
Zoltán Gócza and Zoltán Kollin are two web design experts who believe that people should build websites based on evidence instead of myths. On their fantastically useful website UX Myths, they list the 32 most frequent user experience misconceptions and explain why they don't hold true.
You should read all 32, but I will summarize the #1 Myth: "People read on the web."
- People only read word-by-word on the web when they are really interested in the content. They usually skim the pages looking for highlighted keywords, meaningful headings, short paragraphs and scannable list. Since they’re in a hurry to find the very piece of information they’re looking for, they’ll skip what’s irrelevant for them.
- In 2013, analytics vendor Chartbeat found that most visitors scroll through about only 50-60% of an article page.
- A 2008 eye-tracking study showed that less than 20% of the text content in an average web page is actually read.
- In another usability test, researchers found that concise, scannable and objective copywriting resulted in 124% better usability.
- Ergo, well structured pages that are designed for cursory reading are more likely to be read.