Your opinion, I have taught out of Griffiths, not my favorite book on E&M, much prefer Wangsness at that level, I think the presentation is much better and the methodologies taught to solve problems are not misleading. I felt that Griffiths hand waved the solution to important problems without really sitting down and solving them in the correct manner.Putting Purcell and Griffiths in this list is misleading to say the least, in my opinion. These are without a doubt two of the most excellent books on electromagnetism to have been written. The third edition of Purcell is particularly excellent, the addition of SI units is such a trivial issue.
The list is about books which are so horribly written that no one should read them. Purcell and Griffiths are by no means examples of such books. I don't think micromass meant for the examples to be hyperboles. If we included every book that had a small caveat then this list would include every textbook ever written.