First people want me to DPS with all my dots or they'll get mad(MORE DPS HEALER!), now people don't want me to DPS with all my dots or they'll get mad. Sigh.
Look, if you have specific wants during PuGs, say something at the start of the dungeon. Your team may or may not do as you ask, and at that point you can decide to deal with their choice or leave. Don't expect people to know exactly how you like to do things, then have a freak out when they don't. Not to say you would freak out... but some people do.