Have you ever listened to a politician answer a question only to find out they've said absolutely nothing? The same thing happens especailly for some B2B websites. Marketing people with little or no product knowlege design the website themselves or hire a third party website designer who has even less product knowledge. The end result will be product pages with plenty of selling features and product specifications but little value added content.
For example, I've seen machine tool, metal fabrication and packaging equipment manufacturers' websites that never describe the basics such as: what does the machine do, what are its advantages and why is it better than the competition. Instead the page may be filled with corporate jargon such as we're #1, a global leader, over 100 years of exeprience and other meaningless rhetoric often cited by an inexperence marketing staff.
Over 90% B2B buyers start with an online search. Researchers will favor websites that provide value-added product information such as videos, whitepapers, Power Point presentations that explain the product. This is often referred to as content marketing. When sites tell you how great they are, it really doesn't help the browsers understand your product any better. It's like being at a party and meeting someone who only talks about themselves.