Excellent point well referenced in a review by Steven Poole in last weekend’s Guardian Review section, of the new book of that name by that organ’s ‘production editor and style guru’, David Marsh:

“…and the correct use of ‘whom’, avoidance of which has given this book its deliberately teeth-grating title. Cleverly, Marsh here inverts the usual reasons for understanding conventions. You need to know the rule for ‘whom’ not because you should use ‘whom’ whenever appropriate (because it will sometimes sound pompous), but because you need absolutely to avoid using ‘whom’ when it should actually be ‘who’, since that will sound both pompous and stupid.”

Spot on! Well done that man.