I think it's more interesting to build tooling that helps with the core problem rather than try to change people's attitudes. The problem imo is not that people are lazy, but that the review tooling is not good at the problem set of large changes that need to be introduced atomically.

Even if a change is not enormous, it can still be difficult to grok the context of a change when it's all squished together. Reviewing a series of smaller changes with good context messages is just mentally easier and technically simple (plus ends up with better commit messages for future context).

I've seen Butler Requests come in via our internal usage where the unified diff is still fairly small, but it's much easier still to review it properly when it's broken up into semantically grouped changes with good commit messages.