Plug reading useless

I saw a statement on a different forum that said:

Something to keep in mind....If you're trying to read spark plugs, you're pissing up a rope. Contrary to popular beliefs and arguments, you can have plugs that "look good" from a couple of cylinders with one happy and the other ready to eat itself alive. NOBODY in professional motorsports really wastes their time with that because over time they've learned it is not an accurate way to understand what is really happening.

What do you folks say? Me? Well as far as I’m concerned it’s an extremely valuable skill to have. Just another tool in the tuneup box.