Thanks for the replies.
Basically what I get out of it is that THF isn't invited because of ignorance about the job, specialized party setup, and a misconception of low damage. There's also a stigma of bad players out there that the good THF has to overcome. I'll deal with these in order.
As for the 'bad' THF; everyone can have off evenings, I would hope that anyone playing this game would give a second chance unless of course the lack of skill is painfully obvious. I'm a god THF, but I still have off nights. Pulling links, SATA not hitting, or being on the slow side. It doesn't happen often, but it does happen. (Of course, if I'm having one of those nights I usually start looking for a replacement to save myself and the party further frustration.) Just as in real life, you cannot judge an entire group of people based on the behavior of one or two. When you pt with a good THF, write their name down, hell, add them to your friend list. Don't continue to reward players that have no skill. This goes for PLD, NIN, WHM, RDM etc. I'm amazed at how many of the other jobs have bad players that just keep rising to the top.
The low damage I would like to laugh at. From 30-45 I was running a parser, and would consistently (not always) out damage war/nin, mnk, blm and rng. It starts to taper off after that, and I would imagine that it's going to spike again after 55 and 56, when I gain access to Triple Attack and Dancing edge, respectively. Yes, our per hit dmg isn't on par with a DRK, but you have to remember that we're using toothpicks here. A good THF can pull of 3 SATA's in a 90 second fight. If you take my average (Elvaan) SATA score of 400, that's 1200 dmg in one fight. If of those is a SATA + Viper Bite, that's another 200-300 on top of that. The majority of that damage (hence the hate) get pinned on to the main tank. When the tank has all that extra hate, it allows other jobs to ramp up their performance. Let the DRK berserk + souleater, let the BL overnuke, or the RNG spam arrows/bolts. The tank no has all the hate he normally generates, plus all the hate the THF just pinned on him.
Specialized party setup. Yeah, we need a tank, and someone else to get hate first. Back before I took a 1 year break from this game, there was never an issue with finding a /war. Seems that the side effect of SE lowering Xp requirements is that people are crutching themselves with /nin. I'm all for experimenting with subjobs, but /nin, /rng, /sam, and /blm have their places, and it's not ALWAYS in an XP party. All I need is for someone to grab hate for a second. If there's no one else with provoke, than all that has to happen is my trick partner has to hit the mob. As long as the tank lines up and doesn't engage until I've SATA'd him/her, it will work fine. It takes skill and finesse to play without a second voker, and it's a challenge I like to overcome when I have good players in my party. Fundamentally, FFXI is a game of TEAMWORK, once a party learns to play together, lots of new possibilities open up.
THF is all about hate control. We're here to allow you to do more damage than you ever through possible. We're here to close skillchains with big numbers, and inflate your MB numbers. We're here to pull, and control your XP flow. We're here to control MP usage. A fast THF will keep their trick partner from getting their *** handed to them while they set up.
Remember though, THF can only be as fast as the tank they need to line up behind.
For the record, NIN don't NEED THF. Until they have access to Ni spells, a THF helps, but a good nin will keep hate regardless.