It is a very valid argument. I wouldn't say it is true all the time though. I always ask myself if I comprehend it, and if I do, I go out and bash.
As for Tool, I really like tool, but I can see the other side. When I bought Aenima, I hated it. It took forever before I could get into it, and even then, it didn't grow on me as much as lateralus. I can say that, looking back, I didn't get it at first. I can also see that a lot of people who do sort of get it don't like it. I guess you have to get past certain biases to like something. You either don't get, you aren't open minded, or the music sucks. I think the tool thing is sort of a combination of the first two. For a good example of a band that people aren't open minded about, check burzum. Why does anyone not like burzum? Burzum isn't hard to get, I was in love on first listen! It is too repititous, and the vocals are too wierd, so some paople take that as suckage and let their biases run rampant. Meshuggah definatly falls in the catagory of "you don't get it". Obviously, future breed macheine is easy to get. But, their later stuff is better, somehow or another. THe guy who criticised it, saying future breed macheine owned but destroy erase improve as a whole isn't that great is right. The album nothing is possibly the most complex math metal I've ever heard. I actually explained the polymetric idea on the math metal forum. Check that before you say it just adds to 4/4. Honestly, I guess it does, but nothing like you are thinking. Try to tap 4/4 to anything but the cymbol, which is used to keep time, and you might see it. Try stengah. Listen carefully to that song, and try to tease out what time signature it really is in. If you listen carefully, you might think that every member is in a different time signature, but in reality, it is like a cycle, where the sigs eventually converge. And Catch 33 is less complex and just plain atmospheric mood metal. They are incredibly technical. Just listen carefully to the drums. Very carefully, because a lot of it is hard to hear. It is like fucked up neal peart. The guitarist demonstrates some technicality on his solos and his solo album. I am 100% positive you guys don't get meshuggah. It is really complicated.