Fair or not, the responsibility is on premades to not ruin the experience for everyone. SE has already made it abundantly clear what their position on the matter is. DRK and AST were nerfed specifically in Frontlines last patch. We used to be able to 8 stack and lost that due to the exact same complaints. They are FAR more likely to tamp down the good players than drag up the mostly casual playerbase in Frontlines. If more nerfs come or we lose 4 man stacking there is no one to blame but the few people treating the game mode like it’s ranked CC while the vast majority approach it with the seriousness of Lords of Vermilion.
It’s just the nature of the mode. From holy spamming WHM alliances, to MNKs with double pocket healers to the DRK cheese we see today - optimal strategies evolve and people who love large scale PvP play to win. The difference is that unlike before, when the mode was the domain of a dedicated fan base, it is now firmly in the hands of casual roulette players. We should expect SE to balance according.
As to whether or not the current flavor of cheese is overbearing - my experience fluctuates based on the data center. An Aether team during prime time has a decent chance of managing against a premade, with both teams often punishing particularly egregious offenders. On Crystal - I can mark the DRK, tell the team to guard when they see the mark jump to them, meteor dive the DRK when the premade runs from cover to setup the burst, push the DRK back into their team to deny pull setup, spam danger bongos macros, only to turn around and see my team got wiped by the two ASTs and DRG bursts sans the pull. It’s no wonder to me why I see certain premades data center hopping.
TLDR: As long as the mode is in the daily roulette it belongs to the casuals. Your love for large scale PvP won’t change that. SE will balance around them. Don’t make the game mode worse for yourself by taking it too seriously.