My wife and I did our first six Disney Cruises using points. Our first using points was in 2001 and our last using points was in 2016. Was it the best use of points, in the first few years yes. I used to tell people the value I got on the cruise paid for more then my entire purchase price of my DVC membership, we purchased in January 1997.
The last six cruises with seven and eight currently booked we have paid cash. We vacation a little different now then the way we did in the past.
My opinion is if you have the points to do a cruise and you do not want to be hassled with either renting them out your self or having a broker do it for you to generate the cash needed for a cruise, use points, people do it all the time.
We have a friend who is going on a cruise next year. She is using half points half cash. These are points she has to use and since she owns them it is a way to save a little money booking a cruise.
Is it the best use of points, for my wife and I not at this time however I have been looking at some of the cruise point deals DVC has been doing and might try points for a cruise again.
It all depends on what you are comfortable doing.