AB, as a whole, hasn't really changed. I assume that your question really refers to CB.
In the (not-so-) 'good old days' CB was full of vitriol and petty squabbles. Some people might have found it entertaining but anyone who was posting within the 'serious' parts of AB, and who took a look at CB just to find out what it was all about, was very unlikely to post here.
Now that things have changed, more and more of the 'serious' posters (such as Barmaid, ChuckFickens, Dzug2, VHG, et al) are to be occasionally found in CB, proving that it has become a place where everyone can participate, without fear of being abused or (as frequently happened to me) having their benign posts totally ignored amongst all of the vitriol.