In fact, I tend to agree with you. I would prefer to see cruise lines stick to the model of offering high-quality food and entertainment with no extra onboard surcharges.
But you have to admit we have come to accept alternative dining as a reasonable and worthwhile added value purchase.
If I had a choice of seeing a regular production show or an extra charge show from someone I like (Blue Man Group) I would go for the latter. Especially if it means cruises getting cheaper if I choose not to attend any of the entertainment onboard, because in fact I am not big on shipboard entertainment.
But the cruise lines have to "keep it real."
A good example of where they have complete off the deepend is charging $12 to $15 just for one pay per view movie in your stateroom. They should have recent movies running free all the time anyway, but if they want to have PPV they should only be a few dollars - not $15.
The only time I ever paid that much was a week-long cruise on MSC where I was sailing alone on a ship full of French people and was bored stiff. I did it one time.