I can understand part of why some establishments might have this sort of policy in place, but as an avid computer user I can also understand the frustration of the author of this column. A common complaint in many establishments such as coffee shops is that people will camp out for hours to use the free wi-fi (if available), and maybe justify their presence by purchasing a cup of coffee, though not always. So, instead of being able to “turn over” the table, just as you would in a restaurant, they have somebody camping out, taking up space, and using their computer instead of allowing others to use the space.
However, as the author points out, people are switching over to ebooks these days, and ebook sales are outpacing the sales of hardcover books. Coffee shops do not limit people from sitting down to read a magazine (also available in electronic format in many cases), a newspaper (see magazine comment), or a book. There needs to be some understanding on this front, but I also think that there needs to be some education regarding etiquette in these circumstances. The real problem is those who camp out for hours on end, and those who do that are what has caused so many businesses to adopt such a policy in the first place.
No E-Books Allowed in This Establishment – Bits Blog – NYTimes.com