You're still 1 person in a 6-man team. All it took was one person disagreeing to destabilize the group. Some would choose to do this through disbanding. Some would *****, and *****, and *****, and ***** until you stopped doing what they didn't like you doing (even if it really did no harm). Some would just "stop caring" and thus get lazy, bringing down party efficiency. Some would go on to intentionally sabotage the group, just so they can try to play the blame game. Where any of these scenarios lead could basically escalate to the outright end of the party, or the offending RDM just getting kicked and replaced.
You can say it never happened to you. You can say to just build your own parties (which doesn't solve the problem). You could say to only play with friends (which may work to a degree). In a perfect world, people wouldn't bat an eye. It'd just be another way someone plays the job that works. The whole, ********** off, I'll play how I want!" mentality some have expressed in the past isn't particularly endearing, especially if trying to turn around and say they're still a team player. And yeah, there's a difference between being that and the party's *****, but I think most of us have been around long enough to know that people were happy with having the latter back in the day. Just simple, albeit boring expectations, for a given result. Deviation, of course, could threaten that result. Full circle sheep sheep baaaw ram ewe, etc..
For all the RDM horror stories that have proliferated the boards over the years, the good ones involving the melee types aren't too common. Sure, the FFXI community seems to have an unfortunate fondness for drama, but the reactions drawn are still a reflection of the community. Some are direct from a player posting their own experiences. Others can be word of mouth. And any time a "good" story might come about, you can be sure someone was waiting to swoop in and find a way to tear it down. Low EXP/hr? Their fault. Actually do okay on a parse? Your other DDs sucked. Try to defend yourself? Don't bother, they did the math and are always in superior parties. Always. Such things can linger and otherwise neutral outsiders could be jaded by such happenings. Basically, there's only so much we can do without SE stepping in and basically slapping wrists through code changes.
So, while say I'll the physical RDM of 99 is better than the one we had at 75, it's a scale that's further skewed relative to other classes. Playing ranged has its perks with safety, the ability to fully swap gear, and a higher potential area awareness. Melee invites more risk through AoEs, limits main/sub swapping, and can provide some slight distraction regarding TP and/or WS timing. These "faults" add up, and while they'll never go away as intrinsic parts of the melee experience, the differences between an INT/MATK sword and a magian staff shouldn't be so night and day, nevermind what such a sword user gives up compared to an Almace or STR/ATK weapon. "Melee fodder, Magic bosses!" has been a popular line some have tried to use in the past, but it's pretty flawed for endgame RDMs when fodder doesn't exist (popped mobs), is easily avoided (sneak/invisible), or is just plain too awkward to do (switching atmas a lot in Abyssea). And I bring up the whole "Not in MY party!" line from earlier with the first paragraph in mind as enough people with such a mentality basically means playing alone and/or not quite experiencing content with others in an enjoyable manner.
And as someone who had a lot of jobs under their belt, I'm not really ashamed to say that if something was a better suited for a task, I'd switch to it instead of forcing it. It's not me hating on RDM (at least not when exploits weren't involved), it's just knowing limits are there and have been there for times it perhaps took too long for others to come around and see, but by then, we got what we have now. When you looked past the pink magery, when you looked past the solos, what was left? It's sad it took WHM and SCH being buffed, as well as new content either being built to curb solo or better handled by other jobs to get people asking those questions. "A dead job..." seems to be the unfortunate reply.