Why Must Read The Complete Calvin and Hobbes?

There's not much praise I can give this set that hasn't already been said. It's a wonderful collection of one of the best comic strips of all time. The construction is great, the presentation is great, and I'm very happy to own it. HOWEVER, as I'm reading through the first volume, I've already noticed two changes made to the comic strips. The first, and most obvious, is that the early strip where Calvin asks his mom if he was adopted, if they're going to make him work in a cannery, and if they're planning on eating him has been altered. The question in the first panel has now been changed (not so subtly either, I might add) to "Mom, was I genetically engineered or cloned?" The original wording can be found in the original books, as well as the 10th anniversary collection, so I doubt this was Watterson's intent. The second change I noticed, and the far more minor one, is in a strip where Calvin is grumpy because it's rained the entire camping trip, and his dad tries to encourage him. The original line from the dad is "Some trouper you are!" but an editor has changed it to "Some trooper you are!" despite "trouper" actually being the correct spelling in that instance. I haven't noticed any other issues like that, and I certainly enjoy the box set, but it's disappointing that someone felt the need to meddle with such a great comic before printing it in such an authoritative treasury.