The problem isn't the number of games, it's that they cram everything into 2-3 days, so it feels overwhelming trying to watch everything. If they spread it out over several days (or extend the number of weeks a split is) similar to how every other league does it (the LCK has 9 matches per week spread over 6 days for 11 weeks, LPL has 10 matches spread over 4 days for 10 weeks, LMS has 6 matches spread over 3 days for 8 weeks). This is much easier to stomach instead of seeing 4-5 matches per day (not to mention these are all on a single stream, which is another major complaint that other people have had, I personally don't care, but I figure I'd put this point).
I recall even Riv and Phreak making a joke on PTL that their weekends are now completely filled due to the number of games being played, so this would also allow the casters some more free time throughout the week, and it's not like they'd need to pay the casters more, it'd just be viewership that drops (since you wouldn't have a live crowd on a weekday other than Friday, and teams would compete with somewhat spastic schedules).