Except that expecting the people on other roles within instanced content to do their jobs and perform well is neither arrogant nor rude. Placing the onus for a successful dungeon run entirely on a tank player's shoulders, I would argue, is what contributes to a frayed community. We cannot continue to go along laying blame at the feet of the smallest proportion of players who, as with the healer roles, have taken a very difficult task upon their shoulders.
I expect people on DPS jobs to watch their aggro. I expect them to use their support abilities. I expect them to move at whatever pace tanks set, within reason. I expect them to put forth a team effort rather than focusing on how high they can get their numbers, at the expense of the other three, seven, or twenty-three people in a group.
One of the best things about FFXIV (at least until the SB launch) were the prerequisite class requirements and cross-class actions. There was a mandate with the former, and an incentive with the latter, to play a job outside your preferred role. I feel this conferred a better understanding of what people on the other roles are attempting to accomplish in a particular piece of content, when one had a reason to go and play on other roles for the sake of unlocking soul stones and opening up additional actions. We talk about SMN/SCH applying Virus at a whim pre-4.0, or not using E4E at appropriate times; we talk about melee DPS jobs not paying attention to what mob they're targeting versus what mobs the tank may have marked, or may presently be targeting. If we're going to talk about positive community experience, then we absolutely need to get away from the idea that sole responsibility can or should be laid at the feet of any single role.
I used to slum it up in HW dungeon and alliance raid content on SMN; cleared A9S-A11S on it until my static forced me back onto WAR main for A12S. Having done all that content on a caster job, then doing it on a tank, then flipping back gave me the perspective I needed to understand what I could and should be doing to speed things along and contribute to the party's success without running roughshod over anyone else for my own sake. Yes, I should absolutely hold Virus until I see the "Deadly Thrust" cast bar; yes, I should absolutely toss E4E on the tank after he's pulled and established hate on one group and is moving to pull and establish hate on the next big pack of mobs. Did I accidentally pull hate on one or two mobs with my AoE burst? Hold on, let me pop Sprint and run myself into the tank's face so they can easily get aggro pack with Flash, Unleash, Overpower, etc.
Granted, we have to learn new ways of contributing in SB with all the changes to our toolkits, but in no way, shape, or form should any of us, regardless of what job we prefer to play, operate from a position that responsibility in instanced content is entirely the province of someone else (anyone else!) but ourselves.