Not entirely a numbers thing. In high progression guilds they often don't let you decide what bosses you actually get to come in on in your 14+ roster. THIS is the competition. You can't make much of a case for yourself when you already know that disc/pally is preferable for most fights and that the third healer to put into the mix should be the shaman over you as a druid. This just leads to being sat for almost every progression kill and going days without doing any thing at all as they lock out for a kill or just take a long time to kill a boss.
Disc is so good in 10m that they get to participate in EVERY boss fight unless they simply step out cause they no longer need gear. As a druid most the fights you get in on are farm fights that another healer doesn't need gear from and if leather drops then it's happy days if they aren't running a boomkin, cause it would just be d/e'd.
Our Druid gets in on every fight. What you are describing sounds like a personal problem and nothing more.