Ahh, the Holidays!
Some people just prefer to argue a point vs answering a question that was asked I guess.
It was the US distrubutor for MA that stated the screens have an audible effect for serious listening. Since they are meant to be listened to with the grills removed, it made sense to protect the tweeters with screens as the line is suited for family room theater set ups which may include children. These aren't thin screens such as in a SEAS tweet found on Totem 1s, they are fairly rigid with much more metal between holes. They are attached in a way that offers easy intended removal in the "S" series, not sure about the Bronze.
I actually own have a set of MA speakers with grills and screens on them. I like the sound better without them on because I like a more focused soundstage between my speakers. The screens in place lessens the effect however unbelievable that may seem. The tweeters are easier to localize, period. I also like the sound with certain cables better than others though.
Prove your facts if you must.