Washrooms

I was surprised by a recent article in the club mag that out of 30 members on a club site none used the on board facilites of their van. Although no reason was given as to why. I can understand this if you only have a small wahroom. although i have always used the vans facilities from a tiny washroom to now a full end washroom regardless of whether on a club site or cl, as is my personal preference. Do you use your on board facilities? if not why not?