>On the contrary I can see disadvantage - reading and understanding a history later may become difficult task.
I'm replying to you but this is directed at everybody who advocates squash merge and discourages small commits.
IMO this is a tooling problem, plain and simple. When I am committing to Git, I am using the "write" components of Git which are incredibly powerful. I can commit in as small a chunk as I want and preserve the richest history of all the small changes I've made, knowing full well that the state of the code at HEAD will not be degraded for doing so. If I make two small independent changes, I can feel free to branch them separately and then merge them together to show that they could have been performed in any order.
When you read my history, you are using the "read" components of Git. Unfortunately these are not as powerful. You can do some nice things, like if you want to treat history as a straight line you can use `git log --first-parent` and you'll see only the merge commits (as if all merges had been squash-rebases).
It would be much better if you were able to collapse or expand any sequence of linear commits to gloss over the lower level details. But as far as I'm concerned, this is a problem with the "read" components of Git, not the "write" components, and so I will continue to use the "write" components to their full power. And the best part is that if I do it this way, we can improve the "read" components and allow the reader to collapse my verbose history, but we will never be able to expand pre-collapsed history.