1) If that's true, that's idiotic, because it doesn't work that way. You don't win moderates by posturing as an extremely moderate person. Very few people have an ideological commitment to centrism. If you try to stand in the middle on everything, that's just false compromise, and you look inert and incompetent. If you bounce back and forth across the aisles, you look unplanned and disingenuous. In reality, moderates are either people guided by only one or two issues, or people who just feel like they have no idea what's going on. The best way to win them is to look like you have a plan, and try to quickly bring results that address the common issues. This requires the exact opposite of what the Democrats have been doing for some time.
2) In some cases it definitely is appeasement, spurred by the mechanics of government. People may want one thing, but the Democrats still have to get through Republican lawmakers. Different people are more or less easily intimidated by such political opposition in government (in recent decades, Democrats are typically very easily intimidated). The majority of Americans care more about jobs than the deficit. The majority of Americans want higher taxes on the rich. If Democrats wanted to win moderate and swing voters, they could press those things. They don't because they are afraid of Republican office holders who don't represent moderates and swing voters in that respect.
Do you have any gravitas, or are the livelihoods of hundreds of millions of people an afterthought?