Memes are like genes - in that both transmit heritable information down the generations.
Complaining that memes split culture into little pieces is rather like complaining that bytes split computer programs into little pieces. Computer programs are full of inter-dependent components, but that doesn't mean that you can't split them into pieces. You can. It's the same with the heritable component of culture. Or anything which is composed of information. This is a property of Shannon information in information theory - and has nothing specifically to do with culture.
Genes interact during the process of their expression too. Their interactions are very complex. I sometimes wonder whether those who complain that memes divide culture into pieces have any knowledge about how genes divide organisms into pieces - and how complex ontogeny is. To me, these organic processes also look highly complex.
You can build models of meme dynamics that assume their interactions are linear - just as you can build models of genes that assume their interactions are linear - but these models should not be seen as limiting the entire domain - they don't limit the scope or applicability of the underlying concepts.
Few complain that "gene" is not useful term because genetics fails to capture the complexities of ontogeny. We have developmental biology which looks at that complexity. In many ways, the point of genetics is to ignore and bypass that complexity, and concentrate on recombination, mutation, and so on. It is the same with memetics.
Critics would be welcome to discuss the wisdom of applying the existing distinction between genetics and developmental biology to cultural evolution. However they should first understand the proposal. Complaining that genetics seems to ignore developmental processes won't cut it. That is the point of genetics - it specializes in another subject area. That's not to say that developmental processes are unimportant or unrelated - just that they are not the proper subject area studied by the genetics department.
Critics can keep harping on about how memetics ignores the complexities of cultural development - but I don't think they are doing themselves any favours. From the perspective of memetics, they are just wasting their breath and failing to usefully contribute. We know about cultural developmental processes. Yes it is complex = but it is a different subject area. Memetics studies the recipies and the mechanics of how they change. How recipes make cakes is a related subject - but humans are forced to specialize by their limited brains; so academic topics have to be subdivided - and this seems like a highly-appropriate fault line with a proven history in mainstream biology.
Memes are not ‘practices’, ‘approaches’, or ‘traditions’ - any more than genes are cells, limbs or proteins. The point of the idea is to distinguish between heritable information and its expression. Between cultural genotype and cultural phenotype. "Cells", "limbs" and "proteins" are important concepts - but they aren't genes, and they can't be used to replace the concept of "gene".
To recap, the virtue of distinguishing between heritable information and its expression, is that the heritable information is the only thing that lasts in evolution. Everything else is not passed on, not inherited. For many kinds of analysis, it can be ignored. If you look at evolutionary biology you will see the utility of this approach.
The complaint that memetics is reductionistic has some truth to it. It does, after all involve splitting a phenomenon into pieces and analysing the pieces - and the interactions between them. However, reductionism is bedrock of the scientific method. It is the main way that science understands complex phenomena. Reductionism is a very important tool in the scientific arsenal. If you don't use it you will lose useful knowledge. Essentially, if you think 'reductionism' is a bad thing, you need science 101.
Contrary to your claim, using the term "meme" is not a form of intellectual "laziness". Memes are mostly just terminology for cultural evolution. Practically every theory of cultural evolution that has been proposed has some term for heritable cultural information. Boyd and Richerson used "cultural variant". Lumsden and Wilson used "culturegens", Donald Campbell used "mnemones". Carl Swanson used "sociogenes" - and so on and so forth with dozens of meme synonyms. "Meme" is just the term that won the competition between these numerous competing terms.
It is the best term, I think. It is short, and it is reminiscent of "gene" in evolutionary biology. It also lends itself to conjugation - as in "memetic engineering", "memetic algorithms", "population memetics", "meme pool", "memetic hitchhiking", etc. I can think of no better way to gently remind people of the under-appreciated truths that culture plays by Darwinian rules, is subject to natural selection, and is part of biology. No wonder it trounced its competition.
Over 150 years after Darwin, memes and cultural evolution are finally filtering through into mainstream consciousness. There's an explosion of activity in the area. With scientific growth comes scientific conflict - and on the edges of science tempers can fray, misunderstandings can arise - and there can be territory disputes. However, it would be helpful if the practice of "steelmanning" became more widespread. Creating straw man caricatures of opponent positions and trashing them might be fun - but is not all that productive. Progress in science needs critics that attempt to understand the positions of their opponents before trashing them.