Who is telling you that literally everyone who plays this game is open and friendly? Obviously they don't know everyone, so I suspect they were just trying to express what positive experiences they've had in the game but phrased it in a hyperbolic way. Your mileage may vary, and of course you will not meet the same people or have the same experiences they do.
Personally, I think this game does have a generally kind and chill community. However, that is coming from someone who is still leveling and not doing any extreme/ultimate or endgame content yet. I'm also not in an FC and don't really go out of my way to talk to other folks. So, most of what I see is just who I interact with in towns, open world, and dungeons. And so far, almost 100% of the time people are pretty nice. Players are not scared to say that they're new to a duty, people give tips when needed, tanks ask if they are pulling too much, and if there's a group wipe nobody gets mad we just pick ourselves up and keep going. I often get nice compliments about my glamour, and sometimes random strangers just come up to me and give me items for seemingly no reason without wanting anything in return. Most of the time if somebody asks for a revive in the map chat, somebody else has gotten them up before I can even get there.
What little "bad apples" I have seen so far are: 1) Some of the people on these forums (not naming any names, obviously) and 2) Folks getting grumpy in Alliance Raids because they don't like the Duty that Roulette gave them. Also, people seem to get spicier than normal in those Sky Pirate raids (Dun Scaith and the like).
I have no idea what your experience has been like, OP, and if you have had to deal with some genuine jerks then I'm sorry to hear that. We're all human beings here after all, and some of us are not great people. But every time I hear about how the FFXIV community is secretly bad and it's all a big conspiracy, I have to wonder what circles people are running in and how do they put themselves out there in the game. I've seen people making threads complaining about how "people can't take constructive criticism," and they post screencaps of their dialogue in a dungeon thinking they're the "good guy," meanwhile they don't even realize they are just being needlessly rude and not actually offering any help at all.
Another random anecdote: I was in Golden Saucer once and somebody was calling out how to get an easy 60,000 MGP for the Fashion Report, and offering free item kits as gifts for whoever wanted them. Call me crazy, but I thought that was a pretty nice thing for somebody to do, and counted in the "FFXIV community good" books. However, some random Hroth Bro decided to chime in, questioning publicly "What's the catch?" and basically accusing them of trying to scam people. They explained they didn't want anything in return for it, but Hroth Bro didn't believe it and continued accusing them of trying to get away with some kind of scam. So OF COURSE other people naturally told him off and pointed out he was being rude to somebody just trying to do something nice. Almost immediately Hroth Bro breaks into a "FFXIV community is so bad, look how I am being harassed" tirade. I mean, he could have just admitted he was wrong and apologize, or choose not to engage further, or simply not be silly grump from the start -- but I guarantee you, this dude still thinks he is in the right and he has this great tale of how he exposed the "toxic underbelly of the FFXIV SJW Tumblerverse" or whatever.