Personally, I have no trouble handling the attacks with my Dunmer Vampire Lord Assassin, and I get very frequent attacks as well. I like the attacks, and think it lends an air of impending doom over the DLC until you solve either side of the Quest line.
I just find it silly for people to assume that they speak for the whole community, when there is enough dissenting opinion to prove otherwise. And beofre anyone mentions about the number of threads/complaints, that's a paltry .02% of the total number of downloads that Dawnguard has had, so it's not "most people" who dislike it.

I'm 100% confident if you ask players of Bethesda games, the overwhelming majority like the fact that you can do quests when you like at the pace you like without being forced to complete a particular questline. I'm happy to be proved wrong, but I seriously doubt players want Bethesda to push them to do certain questlines as a priority.
Sure some people like the attacks - that is not the point though is it? Whether you like them or not is totally irrelevant. The point is Dawnguard pushes the player to do it immediately if they want the attacks to stop. That contradicts a design philosophy that is absolutely integral to Bethesda games and is doubtless a significant factor in their success.
If you think otherwise, start suggesting Bethesda should design their games so specific quests are forced on the player - see how popular that notion is.
If you like the attacks, good for you. People that don't like them are FORCED to complete an ADD-ON DLC above everything else to try to make them stop IF they're not bugged for them and will continue regardless. That is terrible game design.
Is Skyrim a game that's all about glowy eyed vampires now? Because it appears they suddenly take priority over Alduin or the civil war. Maybe they should change its name to Underrim or Skyworld.
They're totally pointless as it is as there seems to be no reason why such pointless suicidal attacks are occurring, but it would have been far better if you had to trigger them by actively starting the questline in the same way you have to trigger dragon attacks and can opt to keep them out of the game if you so choose. Then people could choose to ignore Dawnguard if they wish, as opposed to having to uninstall it if they wish to ignore the Dawnguard questline and not still be harassed by the attacks. As has been said on one of these threads already, Bethesda have never before released a DLC that intrusively forces itself on the player in this way.
And it's not a good sign as together with Skyrim's excessive scripted events and stifling linearity of quests, they seem to be moving into more and more linearity. They seem to think if it's an open world that's all you need.