I agree that my post is offensive, but I was offended myself by the original post. If I'm in a warzone, it is frustrating to me for a person to quit either because we're losing OR because they've decided to go do their flashpoint.
It can indeed be frustrating, but this is how i see the situation:
A random WZ is the same as a random FP. It's a PuG (pick up group). Noone owes anything to anyone except performing their role while a part of the group. This means, even if it's considered impolite and rude, noone is bound to stay for the whole match/run. People can leave whenever they want.
Yes, by doing so they put their former team into disadvantage, but this is how the system works. The only things devs can do is either completely forbid leaving the FP's and WZ's before they are completed (which is ridiculous), or implement some sort of penalties.
As a player, you can overcome the said issues by playing in an organized group, let it be a pre-made or a guild run. This is why people organize into guilds, no matter PvP or PvE focused - to have reliable people at their side.
If I'm queued for a flashpoint, it's frustrating for me to have to wait for that person to finish their warzone before they join our queue for the flashpoint. Supposed they're in a tight huttball game and it goes the full 15 minutes? Why should I have to wait for you to complete ALL the content you want to complete before I can start the content I want to start? What makes your time better or more valuable than mine?
Well, you're definitely not waiting endlessly for a person to click his "ready" button. When a FP group is formed, there is a 1 minute window for everyone to accept their roles. If a person doesn't do it for any given reason in the said time frame, he's booted from the queue and the remaining people are placed on top of the list.