Not much I can add that hasn't been said already, but here's the bottom line: You have every right to tank dungeons the way you want. However, you implicitly acknowledge and accept that your way of running the dungeon might be disliked by the majority of high-level players. If you're fine with that, or can justify the slow pace in other ways, more power to you.

I enjoy speed-pulling when the party composition allows for it because it injects challenge into the dungeons and makes you feel really powerful. What have we been leveling and gearing up for, if not the thrill of decimating 10 or more mobs at once? It's a rare chance to use brute force and gear to bend the rules, which fits right in with JRPG tradition.

But I've also made a habit of doing a party/dungeon check before we start and deciding how to tank based on that. With two MNKs at ~4000 HP and an undergeared SCH? Even in Brayflox or Halatali, I'm not pulling more than one or two groups at a time. Amdapor Keep with a high-geared WHM and 2 BLMs? Glorious. Part of being a tank, to me, is having the wherewithal and leadership to make good decisions on behalf of the party, balancing what the party wants with what it's capable of.