After my experience, it's not about being a ranger or a necro or a thief, it's about trolling, plain and simple. Add in sites like Meta battle 'to back it up' and the fact anet just nerf them, then people have a field day.
I posted in another thread about the nerfing of the 'immob' build . It doesn't make much difference, people for their own benefit only look at the 'meta' builds.
For the sake of the argument, it's not what you do it's who you know and i certainly know of rangers who have no issues getting in squads.
No class should be exempt from any content but nothing is done about it.