I am a warzone healer - exclusively healing for the most part, and I notice a huge difference in contribution and effectiveness of the damage dealers. I would like to see more players try to play main heals in warzones, it would make the matches a lot more fun.
That being said, you cannot force people to play what they do not enjoy. This is not a SWTOR exclusive issue. Most all pvp games have an imbalance in regards to dps vs. heals because for the most part, the very nature of a pvp gamer is to be aggressive and do the most damage. Defense and healing typically come in far behind for most player's style choice.
If they changed the queue to ensure there were only a certain number of healers available evenly per side, your queue time would triple or quadruple - is that what you want? I think it's better to tough it out and get to play more often than to wait for just the right balance of players.
Also, for what it's worth - playing a healer myself, I can't tell you how many times I've been in matches lately where there were other healers than myself on my team but they just weren't healing ... sages preferring to only run the ball all the time in huttball instead of pass and heal to their teammates? Seems odd to me but whatever floats your boat I guess. The point I'm trying to make is, even IF they created a queue where healers were required, that does not guarantee the required healer class is going to do their job and you will have a better match.