It's easy for anyone to "calculate" how long the tournament should last theoretically, but as we saw last year, these things unfortunately just don't stay on schedule.
2x bo5 sounds cool on paper but it's not really realistic. people get burnt out and start playing like garbage after that many intense matches in a row, not even including series they might have to play before finals. when's the last time you saw a team play 10+ wargames in a row? most practice series only last 3-4 games, and a large part of that is because players get burnt out. it's just not possible to play at your best for such a long period of time, especially if you're playing against a strong team and having close games.
it's ideal if we showcase teams playing at their best, not showcasing which teams have the most stamina and can play wow for 8-10 hours on Sunday night. I for one would rather not have to sit there until 5 am like last year as well.