As much as I love Frontline, the fact is, it's a casual mode designed for casual players. With 24 players per team, there's a massive diffusion of responsibility that has pros (each person needs less individual skill) and cons (some will think their participation isn't necessary), not unlike alliance raids. On top of that, you also have sore losers and early quitters who will pout, protest, and otherwise do nothing if their team isn't winning; they don't have the integrity to try their best, whether they are winning or losing.
Removing rewards will drive away the target audience and essentially kill the mode. Furthermore, it doesn't solve the problem of sore losers and early quitters. Shrinking down the team sizes and lowering the diffusion or responsibility will also not help based on what I've seen in FFXIV's 4-man content, Crystalline, the Feast, and other PVP games that are as low as 3v3. GMs should be more active patrolling PVP modes and dealing with people who are not playing in the spirit of the mode, but if we're being honest, they have so many issues (some of their own making) that this is a low priority.
If you're wanting something more serious, I suggest participating in Frontline queue syncs. Otherwise, queuing with friends or people in party finder can allow for some strategy despite what everyone else is doing.