Here is Maurice Bloch in 1995:
In sum, the culture of an individual, or of a group is not a collection of bits, traits or memes, acquired from here and there, any more than a squirrel is a collection of hazelnuts.
[For context for the quote, see [here.]
My usual (patronizing) reply is that it's a basic scientific modeling technique to split thing up into pieces and analyze the pieces. It's called "reductionism" - and it is one of the most successful tools in the scientific toolkit.
Nonetheless, some anthropologists apparently think that memeticists focus too much on the bits of culture, and not enough on how the bits interact.
My way of framing this criticism (within the terminology of memetics) is that they are saying that memeticists focus too much on the memes, and not enough on meme contexts. By "meme context" I mean: everything else in the universe, apart from the meme in question.
However, I think that phrasing the criticism this way illustrates that there's a grain of truth to the accusation - and also suggests why meme contexts might be being somewhat neglected: they are large, complex and difficult to analyze.