I agree.
I just like the feel of a big day moment. Not a big weekend moment.
I don't even watch wrestling as consistently as I used to, but nothing beats Wrestlemania Sunday and getting with the crew to watch. Which I and many others would certainly not have two parties for two nights of WM. The diehards would, but not the casuals.
WM is almost similar to the Super Bowl. Which is why the Super Bowl is the best of all the major sports championships. It's a one day, winner take all EVENT which makes the day special. Not dragged out over multiple days like MLB, NBA, and NHL's big championship events.
The crowd wouldn't be able to maintain the intensity for back to back days either. (not to mention the whole week...what, they'd have to make Takeover take place on their Wednesday night now(?), put the HOF at Thursday, keep Smackdown at Friday [cuz FOX damn sure aint paying WWE all that money to have them punt their show during WM weekend], and then do the 2 nights of WM, followed by RAW on Monday)
I get the argument for two days and wanting to allocate each match their deserved time limit and the idea that it helps pace the show and fans better...but when an event is one night only it brings so much value to the show.
So again, keep it one night and have the best matches/stars make the show...if you don't, tough luck.