I am more than happy to be "challenged" by anyone on my opinions. In fact I gave BALPA a chance to challenge me just last month when I wrote to them rescinding my 17 year old membership whilst highlighting all the reasons for such a decision. Needless to say their response was not overly challenging, as such my access to said forum is limited (a great loss to my life I am sure).
I am not quite sure I follow your logic regarding the anonymous nature of this forum, is an opinion only valid if it's from an identifiable source? I don't believe any of my comments, feelings or opinions are anything to be ashamed or embarrassed by and I would freely express such views to anyone in person.
Just to be clear not all my posts are negative regarding BA, there are some good points about working there and I have highlighted them as well. But for some people trying to make difficult decisions regarding a possible future career at BA my experiences might well be considered "constructive", if not they are welcome to ignore them.