The logic EU appears to be the fact that a small minority of pax take the mikey by bringing everything in bar the kitchen sink!
I have seen hundreds of times pax getting on board with 3+ bags and then getting all angry when there is no space for their precious stuff! Unfortunately a small minority have spoiled it for the rest of us! The rules are fairly simple and fair, one bag per person (size permitting) you have more/ bigger bags check em in and pay. Thats the rules don't like it don't fly simple.