The value proposition for DLC will always rub some people the wrong way because there is no way around the fact that it's less efficient to make piecemeal content after the crunch time of primary development has passed. In other words, people have to be paid, and they get paid the same salary even if they're working on single DLC missions at a time, rather than a huge set piece involved with the base game.
Though perhaps the way people should be looking at it, is that with a game that has a ton of content (this FE is apparently lengthy and packed already) you're getting a great value for the money in the base game. The DLC is just more in scale with what it actually costs to make stuff.
I have to think that the era of (quality) F2P games may break people of the ingrained mentality of seeing a game as 'incomplete' if it has stuff you just don't want or need to buy. As long as the core game is a satisfying package, it shouldn't matter if there's optional content for people who want it.