I think the problem is more that those who drive 4x4s and people carriers sometimes find them difficult to manoeuvre, hence they will do thinks like parking across two spaces and taking hours to wriggle into and out of spaces in multi-storey car parks; and because they are big cars, they are all the more noticeable.
The last six words are the only true ones in that statement, Ici! Oh, and the key word "sometimes", of course
Believe you me, I have sat for an absolute age on many occasions whilst I wait for the driver of a small car to try to wriggle into a parking space. This is simply bad driving, nothing to do with the size of the car at all.
I also agree that it is not necessarily jealousy, more an inbred, unjustifiable blanket hatred and prejudice of something some people just do not like, so it is easier to label ALL people driving a certain style of car or looking a certain way.
I've driven cars of all sizes in my 36 yrs of driving, including Minis, Renault 5s, Range Rovers and all sorts in between (on my third RR now in the last 17 years). I also drive our work vans, including a long wheel-base Mercedes Sprinter (quite big). I have no problem with parking, so highly object to being lumped in with a certain perceived stereotype, just because it's easy for a certain section of society to do so.
It still all boils down to good manners, pure and simple. If OP had asked nicely for the owner of THAT car to move up a bit, I have no doubt she would have done so quite happily.
This really has turned into a 4x4 bash-up, hasn't it?
and
and also a little 
And now I think I'll go out for a ride on my 