I link to the BMJ all the time through work, they have never complained.

Also, the author is cherry picking the text he quoted. Here is the full text from the BMJ groups T&C:

"You may link to articles or the home page of the BMJ or BMJ Journals websites (excluding BMJ Careers and Veterinary Record) but with regard to any other of our websites, you must not deep link to any of our other websites or link to our home pages without our agreement in writing. You may not provide a link which suggests a form of association, approval or endorsement on our part, unless we have expressly agreed to this in writing. We reserve the right to withdraw any linking permission upon notice to you or by amending these terms and conditions."

I would argue they are pretty fair as the majority of their content is on the main BMJ site or on one of the microsites of their journals. (I am not associated in any way with them.)