[ Did you read (critically) the comment I was responding to?
I mostly agree with your statement, except for the implication you may be making that agenda always has this pejorative meaning. It simply doesn't. If you want to understand people, you should not assume that it always does. And we should not police people for choosing to bring the non-pejorative acknowledgement of the fact that groups have purposes and goals.
If LGBT groups did not have agendas, they would not be worth supporting. ]
Writing is an act of art, and reading is an act of interpretation. These secondary definitions come into play when determining what someone means. Agenda is not purely pejorative, and it's true LGBT groups have agendas - they have plans of things to be done - they have motives - reasons for doing something. However, these attributes of LGBT groups could also be described with words that do not have any negative aspects, such as goals, plans, purposes, etc.
>If you want to understand people...
I assume people understand the words they use and intend to use them. If people use words without precision, how can they expect to be understood?
As for etiquette... no idea ha. Made the same mistake myself.