As the owner of a VW Transporter T5 "commercial vehicle" and a twin axle caravan I feel I can comment on your observations.

I have owned volvo estates and big 4x4's as commonly used by club members in the past and found that most of the time they are just too big and uneconomical for every day use. My daily car is a small economical VW Polo.

My "commercial vehicle" is without doubt the best tow car I have ever owned. Yes I can use it for work during the week but when towing it comes into its own. It is very stable at motorway speeds and returns around 30mpg when towing.

I can put all of my caravan equipment in the back along with bikes and surf boards etc. 

Yes I get funny looks from some members but hey each to their own. I don't judge other people's life choices so don't judge a book by its cover.

As for people working in the area I don't really see the problem. Surely this means the site will be nice and quiet during the day for you. If people are paying to stay surely it is entirely up to them what they choose to do with their day.

From past experience staying on various sites I find the "workers" are some of the cleanest, tidiest, considerate and quietest people on site. 

At the end of the day we are all members of the same club.

I’ve come across a lot of commercial type vans on sites and I guess they are club members.  None of these folk have misbehaved or made a nuisance of themselves so no problem.  If I’m by myself on site you may well observe me leaving the site in my CRV before 7am and returning after 6pm, what am I doing......   

I think on site behaviour is far more important than what people do off site. 

There is the 21 day rule though, do they go off site then or not stay that long?