As someone that isn't a frequent visitor to WDW, I'd hate to see one entire park closed while I was there. For regulars that don't want to waste a days entry on a half closed park, just pretend it's not open! We very easily spent 9 hours there in May, and if it wasn't for DD5 getting tired and whiny we could have stayed until closing. We didn't do everything there is to do, none of us rode RNR because DD is too small, and I was disappointed enough in leaving that I considered going back after DH and DD got settled at our resort for the night.
DH and I both previously visited WDW in 1981 and had one of the parks been closed for our recent trip, we wouldn't have gone when we did. We planned it as a once in a lifetime trip for DD, but loved our time there so much that we plan on going back again as soon as DD is tall enough for the rides she was too small for this time (so, 48 inches tall - 4 inches to go!), and DH and I plan on a trip for just ourselves either this November or next.