All fair points, if not good ones...but I have long been an advocate of doing whatever is necessary as a coach to give your team the best chance to win games, and not being able to play a zone is more than just not having practiced it enough (although it does require putting time in to work on it obviouisly...that said, ALL of those guys have played zone defense during their long careers at some level and to some extent most likely, as it is prevalent in AAU).
I don't buy the notion that being able to play man and zone is a drain on practice time...or that practice time is the precious commodity suggested...I know that it is early on and with newcomers, but, there is more than sufficient time to be able to have worked on man and zone defense, among a multitude of other things.
Purdue has had games where playing a zone would have provided them a better opportunity, if not the best opportunity, to win...Monday night may have been one of them...if Purdue does not improve at preventing dribble drive penetration (that leads to fouls on their bigs), it will have other games where playing a zone will provide them a better opportunity to win as well...and it should be something that is available as such.
As for Haas' rebounding...I don't disagree with what you had asserted, yet, with the size advantage that he had (and most often has), three rebounds is not efficient in any sense...a guy that big and around the basket is likely to have three balls simply fall in his lap over the course of a game (and that may be what actually happened given your suggestion that he is an "area rebounder)...if Hammons is in that game, I am certain that he comes away with more than three rebounds...so, while it does have to do with being an area rebounder in a sense as you had alluded to, there is more to it as well in that it has to do with the individual also (no finer example of that than Swanigan for that matter).