Why do stop searching in QM triggers queue dodging penaltiy?

It’s a known issue that if you stop searching in QM it minimizes the window rather than actually leaves the match queue immediately, but interestingly when I quit the game after stop searching in QM, the next time I start the game it shows I have an automatch cooldown. Is it a bug or by design? How can I be abandoned for 15 miniutes just because I quit the game when no teamates and opponnents were matched in a 4v4 QM?