Because of the word "all" in this statement, it is false.
Of course, two people who are making the same business presentation may have very different results. The person who can present with more personal dynamism and who can connect with their audience is much more likely to get sales or to have their plans approved.
However, the better presenter, the one who says things in a good way, will not always win. No amount of presentation or personal charm can make up for a plan that is fatally flawed. The content of a business presentation, or the product that is being sold, is going to have a great deal of impact on whether or not the presenter will accomplish his or her goal.
So, both what you say and how you say it are clearly important. It is not all about how you say it.
When reading this quote I immediately think of body language, and how much of an impact your body language has on your message. Imagine speaking to someone with their arms crossed versus someone with their arms at their side. Nonverbal communication makes a huge difference.
This refers to the important issue of what the components of communication are. The answer is that Communication has been segmented into 3 distinctive components- the Verbal or the language based part, the Nonverbal which deals with body language etc and that is not conveyed through language or words and thirdly, paralanguage which is to do with how we use elements like tone of voice, pitch, accent, diction, speed and volume to convey the message.
The quote in your question is correct to a large extent. As Albert Mehrabian has said, verbal language constitutes only 7 percent of your communication whereas the nonverbal (55 percent) and paralanguage (38 percent) form the 93 percent. He however qualified his theory by saying that this holds true mostly in communication that has a lot to do with emotions and feelings.
However, experts agree that the "how" of communication makes a huge difference to what you want to convey and what is understood by the receiver of your communication. For example, if you were to say "Sit down" to someone in a normal voice, the paralanguage indicates a normal state of affairs. But if you were to shout and say"Sit down" to the same person, the meaning of your communication has changed completely. So it is not just the words you use that sends the message but also how you say it for the right message to be conveyed.
Business means to sell the product and generate revenues by all means.
For a product good or bad is sold basely on the way it is presented or advertised to its potential buyers.So it all depends on how you present.We can see lot examples of good products not making good sales and bad product making decent sales.