Should you try to hold the reader's interest when writing reports that are written for business executives?
I write and edit a great many business reports - I am a freelance writer as well as teacher. While the language of business writing has a professional tone, it is still important to catch the reader's attention. The method is a bit different, however. You may have been taught to have a "hook" to grab the reader's attention in the first paragraph of your writing, but usually in business writing, the hook consists of a concise sentence or two that indicates what the report is about. In the first paragraph, you should give a good introduction to the report so the reader will be motivated to read it and not skim it, as many business people try to do. Business people are busy, so it is extremely important to be concise and direct. Do not use a lot of flowery language, unnecessary words. Adjectives and adverbs should only be used when necessary. Sentences should be strong and brief. Mix them up. Do not use a lot of complex, compound or complex/compound sentences, one after the other. Usually, cleverness and humor are not appropriate, but this depends on the industry.
There are many examples of business writing available online if you want to see some concrete illustrations. In the work that I edit (the writing of others), I find that many business executives do not know how to properly construct a sentence. Their writing is disorganized, more like stream-of-conscious, and the ideas are not orderly. I do a lot of rearranging. Each new paragraph should have something interesting, or important. Also, by using headings, subheadings, italics, bold and other editing tools, you can capture peoples' attention. Much of my writing is transferred to Powerpoint slides, so again, it must be concise.
I would say that you should try to hold any reader's interest on anything that you write. Remember that the purpose of writing is communication, and that effective communication requires the reader's attention. This attention comes naturally if they are interested, and the message and information you wish them to receive is much more likely to arrive on target if there is some interest on the part of the reader.
Now, in the business world of course, such a report needs to be professional, and conform to a format that is acceptable for the company you work for and the various people who read that report, but the use of language and how you arrange it is under your control, and if your reports are interesting, they are much more likely to be noticed and valued. The exact same thing goes for the author, who is more likely to become noticed and valued by his supervisors.