About on those long term holders then it wont really be that much of an issue into holding their position yet they do know on what are the ups and downs of this market which simply means that they are already getting used to it and instead of freaking out on the time that the market would dip on then they do rather accumulate as much as they could considering that they've been pretty aware on how things do behave.
Not all will do about what you say. Quite a few people freak out when they lose hundreds of thousands of dollars, and long term holders are no exception. After all, not all holders are from upper and middle economic circles where they will be able to control their emotions about market fluctuations due to the strength of their money. But some holders from lower economic circles, will definitely panic when the market crashes.
About accumulation, it can be done by all holders especially if they have enough money to invest it. Therefore, I think quite a lot of people just hold without accumulating because they don't have the money to do so. Normal, that is of course conceivable.