Hmph. Fun != spontaneity, not in all cases, nor does "not fun" mean "not useful." The adults who were trying to "placate" you may well have been acting on the knowledge -- one that only wise people come to, regardless of age -- that words spoken in anger can only be expected to hurt. You might think you were getting somewhere... but you can say the most reasonable thing in the world, and if you say it in a hurtful way, your partner can't be expected to listen. We're all standing apart, restrained from getting too close, and through conversation we toss ideas to each other. Good conversation is a matter of improving your throws. Fighting is a matter of hurling your words really hard at the other fellow's head. It's a losing game.
Structured conflict resolution and cognitive behavioral therapy are examples of disciplines that seem cajoling, dishonest, and generally life-sucking... but their aim is to return rationality to the discourse, so that your experience is based on actual problem solving, rather than acrimony and escalating violence.

Of course, the adults may have been wrong anyway. Here are two alternatives to the generous model above:

1) They weren't trying to calm you down so you could talk out your problems; they were trying to squelch the expression of conflict in the hopes that it would make everything magically wonderful.
2) You weren't really in conflict with each other in an intolerable ideological sense, you were just blowing off steam, and were close enough that your friendships could endure it.

It sounds like there's some evidence for (2), so perhaps you're right in your condemnation. I just feel a need to speak out against the premise that when something is no longer perfectly natural and unguided, it's lost the potential for honesty and goodness. Also that if you have to do something that's not fun, it's invariably carrying the whole situation farther and farther away from ever being fun again.