Broadly speaking, I have tired of being implicated as "elitist", "coercive" and another drudge (even unwittingly... and, frankly, that may irritate me more) in a right-wing conspiracy to take over the world. I imagine those who use a virtual academy probably feel the same way about being branded as lazy and uncreative and unschoolers as also lazy and neglectful.
It's funny, though, I don't really have a problem with threads that are created to ask - even pointedly - questions about a certain style. Really, even philosophically "bashing" threads aren't much of an issue; they're generally great sources for finding good information about the practical application of a particular style and lots of external links because people here tend to have lots of resources to use to dispell misinterpretations.
Some of those types of threads have led me to a much better understanding of the various styles of homeschooling and have led me to a place where I can embrace fluidity of hoemschooling and the changes that have and may come about in our styles, not as failures but an inevitable part of our familiy's growth.
My irritation comes up when somebody is clearly looking for support - asking for ideas, resources or other help - regarding whatever path they feel is a good fit for them and their family and a whole slew of people who clearly do not feel the love for <insert topic here> jump in to tell the OP why what they're doing is wrong/harmful/useless/whatever. It's not a matter of "I tried x and wasn't fond of it for y reasons". That seems to be the type of information people are looking for. Sometimes, though, the responses are akin to answering a post requesting reviews of breast pumps (on the breastfeeding board) with a dissertation on why the OP doesn't need a breast pump, that breastfed babies should never be given a bottle, that mothers should never have to be separated from their infants, etc. I can see where someone just starting out (new homeschooler, new mother) could feel very stressed getting seemingly hostile answers to a question not asked.
Just my 2 cents (or 500 words) on the subject. I thought I'd noticed a change of tone, as well, but I've ceratinly not been around as long, nor as prolific as others on the board.