This is only an actual observation, you have to watch overall delays during a year. Sometimes it´s just bad luck that hits you, but with a tighter turn-around you would have seen even more delays than that. There will be months where this flight has no delays at all.
Turn-around times here are an average of all kind of turn-arounds aircrafts may have anywhere in the world with any kind of traffic or schedule or service pattern. Sami plans to vary turn-arounds according to flight-times in the future, as I understood it.
He personally doesn´t expect you to plan them always to reach 1%(one of his seldom comments), and I just experimented with that and did just fine having them at 8,5 %.OK, quite a lot delays at winter time, a little hit on CI,but you can make it up with a bit more marketing.
I´m not a very frequent flyer, but leaving gate just on the minute is something I seldom saw in RL, you are lucky if you leave half an hour later.Most of the times you still reach your destination on time, though.Delays in-game don´t have any consequences on your continuing schedule, so their negative sides are marginal, compared to real life.
Everybody has to work with these numbers here, everybody is free to use them at whatever risk of delay.And trying to turn a bird in record time regularly will see a lot of delays in RL, too.
Sami also designed turn-arounds with the old-fashioned full service airlines in mind, where you really have catering and cleaning (by third party, not by flight attendants), with occasional difficult express cargo and luxury luggage to handle. Modern times slave-driven tin-cans with cattle on wooden seats still wait to be modeled.