I have been reading the negative comments and complaints on here, and have some random, incoherent thoughts.
1) MSC (and other cruise lines) went from having nearly empty ships sailing at great losses to being overbooked, seemingly overnight. If you look at this from a business standpoint, you can't overstaff the ships when they were empty; you were already bleeding money. There does seem to be a problem getting staffed back up, but outside forces played a role in this. And probably still are. Why are they overbooking? See the bleeding money comment.
2) MSC's price is considerably cheaper than other lines in the same category (RC, NCL, Carnival). I view them as Frontier and Allegiant vs American and Delta, as far as amenities. They are a great value for the money, but you have to follow the rules, as we have found flying the new group of low cost regional airlines. You have to abide by the wifi and drink package conditions. I believe the easy plus and wifi are available as an addon at the time of booking for about $300 per person for 7 days, and have seen it as low as $150 if memory serves.. This is a good deal, but has qualifiers.
3) When you combine low fares with unlimited access to alcohol, you will get customers that drink too much and are rude. You also get people that will go for lowest price and want to make sure they get as much as possible out of their vacation, partly because they don't have a lot of money. This point is a little controversial. You can't hold MSC responsible for this.