Sorry, I didn't have time to read all these posts, but, it is obvious by seeing the number that the OP has struck a nerve with many people. So I have just two things to say about it.
I don't think that the intent was to imply that one should leave a baby at home, it was more of a... Why would you want to go with all the stuff that a baby requires to maintain. And Yes... I have had children which is why I feel the way I do about it. They are a lot of work at that age, a lot of work! It is hard to relax and enjoy the experience when you have such a responsibility and have to deprive yourself of the total experience.
For the reasons I stated above, that was also my policy. I wouldn't consider bringing any child under the age of 6 to a place with all the stimulating input that a Disney Park has. I wouldn't consider dragging diapers, special food, about a thousand changes of clothing along on what is supposed to be a fun, relaxing trip shared with the family. Someone in that group is going to miss out on a lot of things that you paid big bucks to experience. My first visit with my children was in 1983. My two children at the time are now over 40 years old and both of them still remember just about all the details of what they saw and how they felt. After my kids had grown up I decided to take them, their husbands and children to WDW for a family trip. The same rule applied. As soon as the youngest made it to 6 we went. Everyone remembers the trip, we talk about it often, both the adults and kids are involved and talk about their first visit. I don't think that people that bring them younger are wrong, it's just that it seem to me that the entire family shared experience that Disney Parks were designed to provide is lost when one is not conscience of where they are and at least one other has to forfeit their own experience to care for a tiny life. It's a nice place, but, not really worth the hassle in my mind.
Again, just so no one thinks that I am against others bringing their infants in, I am expressing my own personal feeling about the situation. Everyone, of course, is free to do whatever they please!