Okay, stop me if I’m saying something people have already stated, but I have my own opinions on Rangers. And I have to address an issue with the OP.
1) what you played back on Guild Wars didn’t matter, the gameplay is entirely different, so you have not really been playing a Ranger for 8 years, more like a bit under 2. I’m not trying to diminish what you’ve done, but bear this in mind.
2) the fact of the matter is, Ranger is just a subpar Dungeoneering class. Do not get me wrong, Ranger is not a bad CLASS. It excels in plenty of fields, but Dungeons just aren’t one of them, for one reason or another. So even if you’re an amazing Ranger, an equally well played Guardian or Warrior is probably going to outperform you unless you have a VERY specific build, and therefore people are going to want them over you. And the vast majority of Rangers I’ve met in Dungeons, sadly just go for a very bland and basic “Spam Longbow attacks, never move from your position, and have your pet aggro mobs that no one wanted to have drawn in”. There are about 3 exceptions I’ve met, but even though they were wonderful players, it doesn’t change the fact that I cringe when I see them join our party from LFG.
Now don’t get me wrong, I’m always hesitant to let a Ranger into my party, but I will NOT boot them, unless they have proven they’re a jerk, terrible player, doesn’t follow instructions, or any combination of the three. (I actually used to do weekly dungeons with at least three Rangers, who know who they are if they see this post, and it rarely ended without us being wiped at least three times, and they were all wonderful people, followed instructions, AND, outside of Dungeons, actually did pretty well if not amazingly well in PvE)
3) this is a personal issue, but you saying how great of a Ranger you are, makes the warning meter in my head go off. I’m not saying you’re lying and I’m not saying you’re blowing smoke, but in my experience, it tends to be the people who brag the most who tend to perform the worst, no matter the scenario.
4) I don’t know how much gold you have, but if you are swapping your skills properly for each dungeon group, you must have a LOT of excess Gold, or you’re just flat-out not really optimized for the role you’re switching to with these new skills. To really optimize for a new role, you don’t just swap a weapon and change your 6-0 skills, you need to re-gear and get new armor and weapon stats.
And yes, there are a lot of people who are badly playing other classes, but the issue I see is… well, that I don’t see them nearly as often in Dungeons as I do a terribly played Ranger. It’s no offense to the group of people who actually DO play it well and are good team players, but it really doesn’t help the group as a whole.
And before you ask, yes, I have a Ranger, but no, I really don’t even intend to get her into Dungeons. I have a two different Warriors, a Thief, and a Mesmer if I ever want to Dungeoneer, all at 80 and properly geared.