Whatever mode you are playing in, if there are 2+ people who still want to play/think you can win, you have made a commitment to your team. You didn't see the Dallas Cowboys /ff when they were 3 of their best players down and loosing like crazy. Give up = 100% loss. Try hard = ALWAYS a chance of winning. You're already in it, so if your teammates are still up for the challenge, don't give up! This is a TEAM game, and not just about the desires and feelings of ONE player.
Also, perhaps modify the way you present your request? I'm much more inclined to agree to a surrender if someone says in chat something like "Hey guys, I think this one is gone. Can we /ff so we can all reque and try again and hopefully get off to a better start?" or whatever, virtually anything, than a random out of no where "____ has started a vote for surrender" with no explanation, or even worse, someone who starts raging and insisting on a surrender or they will feed/afk/QQ. I will almost always vote no, no matter how bad the situation, for those people.
Communicate with your team more. Present requests as REQUESTS, not things you DEMAND of your teammates. Offer suggestions in a POSITIVE and supportive way rather than flaming. We are all PEOPLE playing together, not bots. =)