Instead of just listing off a bunch of reasons I'll just jump right into it. First of all I don't like it when death knights tell me what totems to use. Key word being "tell". Of every other class that's out there I have only been asked if I could use certain totems to help people. Windfury for the melee or wrath of air for the casters. Before the combined Strength of Earth (Attack power or strength I honestly can't remember because of how little I look at the tool tips anymore) and Grace of Air(Agility) I had to nix windfury and wrath of air right out since more agility was always a good thing for me. For some reason though Death knights seem to think they know my totems better than I do and thus "tell" me what I'm supposed to use. Personally I don't really care if they have improved icy talons and thus my windfury totem isn't required (except my windfury totem is always up compared to them always having icy talons up). Or "Don't use SOE totem" is something I've heard all to often due to their Horn of Winter buff (which oddly they don't remember to keep up at all times and they forget my totem has +Agility as well as +Strength as well as my totem being better since I put in the talent points. Why else would my totem overwrite their buff?) Personally I think I should start saying "No YOU don't use horn of winter" or "YOU don't need to worry about what totems I have down". I don't remember seeing DK's have totems last time I checked. Plus I am the master of totem dropping.
Secondly I would like to point out that DK's seem to be much needier in the "What's my DPS look like" category. Before WOTLK I would occasionally see people report DPS but mostly as a standard for themselves to see if they are improving in dps as they get better gear. After WOTLK hit and there were DK's running amok everywhere, every group I was in there was a DK either reporting the DPS to the group after each pull or requesting it to stroke their own ego. Hey if I had a bazillion aoe attacks I'd probably be topping the charts with little or no effort as well. Personally I like my dps. I shred through things dual wielding fists of windfury death (and occasionally off handed flametongue). In fact I don't like DPS meters anymore because people use them all to ofter to try and say they are better than everyone else. Granted if someone is doing abysmally on dps they should look at what they could do different to change that. I don't think people should berate them on their low dps with no suggestions as how to improve it (most likely because said person has never played that class before). But all this ranting about DPS meters is something for another post.
Those are my big pet peeves about DK's, which amazingly enough don't bother me in the slightest when I'm resto. Partially since I don't use any of the totems that overlap with their buffs since I'm casting and they are pew pewing, and partly because healing/sec meters really aren't good indicators of whose healing is the best so dps meters are a moot point for me. I just sit back and throw up and Earth Shield every once in a while and chain heal during the aoe damage. As enhancement I've learned to just ignore the *cough* requests *cough* of DK's because my totems are there more that just for buffs. There there for the atmosphere. And we could all use a little more atmosphere when it comes down to it.