Well how much fun do you think YOU suck out from rest of your team’s free time with that attitude, if your main goal is not winning, but rather having “fun”, experimenting or something else? You are allowed to have fun in QM but everyone in the match still expects you to try your best. Being a complete idiot in this mode is also frowned upon, just as not picking a healer in Brawl mode will make your team mad, because you will spend more time afking waiting to regen than actually playing.
Personal motivators should never be prioritized over winning. That’s the reason why all quests disregard their criteria completely and are completable in all draft modes regardless of satisfying said requirements, so you don’t mess up the game by failing to pick a healer because you have the quest to play something else. The very same reason all special event quests in this game have an added requirement of winning in addition to their usual stat-padding requirement, so that you have to walk a fine line between choosing to end the game when the opportunity presents itself, and risking to delay the victory so you can complete the quest by playing one game less. Otherwise people would just do whatever they are tasked with, losing teams would be farmed by prolonging the game, and you’d even risk losing by giving the enemy too many comeback opportunities, which are not rare.
You’re making too much drama around winning a single game match. With that attitude I wouldn’t want you on my team either, so whichever keeps you out the longest no doubt works best for the population of the game.
This is a bug report forum first and foremost. I could suggest you to make a post in the general section but nowadays with the removal of downvote feature I wouldn’t take any satisfaction from it. The change to requiring you to win the game to clear leaver status was made in good faith and is not at all unreasonable. Sure there are things such as 15 loss streaks, but that pretty much might as well be due to you tilting or playing bad. No reason to toss over responsability to other players. It is not particulary hard to maintain a 50-50 record, even when playing alone.