Having a competitive match end in a loss after a teammate leaves feels bad, even more if the match was equal before hand. A few suggestions to consider: 1. If a teammate leaves early in a match, allow the rest to leave without penalty after a certain amount of time. Pros: You won't lose a match before it even really starts Cons: Potential for abuse, with a fireteam (as long as one player doesn't mind taking a loss and other possible penalties) 2. Adjust glory for the leaver's team so that they lose less on a loss and gain more on a win. Pros: Incentive to remain in the match and try to win, as there is more to gain and less to lose. Cons: Potential for abuse, as above. More of a concern for competitive carries/glory farming. 3. Lock leavers out of all crucible matches until the competitive match they left ends. Only option is to rejoin the match. Pros: Less convenient to ragequit and just re-queue. May get more rejoins. Cons: ? 4. Adjust the glory gains for leavers by degrees. Each game left lessens glory gains by a greater amount, for a certain amount of time or number of matches. Pros: A much stronger reason to not ragequit a match. Taking a loss is better than quitting and looking for a better match. Cons: Harsh for unintentional disconnects In general, competitive isn't taken as seriously as it should be. Competitive should have a higher level of commitment than other PvP modes. I feel like attaching pinnacle weapons to competitive play was a mistake in this regard; competitive should be a choice for those seeking glory, not exclusive weapon rewards. I'm less concerned about people being locked out of weapons and more about competitive being filled with people that simply aren't interested in competitive.
If any of your teammates leave, you should be given access to their bank account. The rest is up to you.