The main problem I see is that code is read left to right, top to bottom (for the most part) but it is rarely, if ever, written that way. The order that decisions are made is almost as important as the decisions themselves. But, we lose almost all of that order or 'context'. Worse, although we can place comments in the code, we cannot attach comments to the evolution of code. Evolutional comments could describe why things are changing in the proper context and make reading code a lot easier.
> we cannot attach comments to the evolution of code
I guess Google has spoiled me. When reading code, I constantly look at its development history - commit messages, diffs and line-by-line "blame", linked bugs and code review threads. If you have good tools for that, there's much less need for inline comments.
