In reply to Justin Tadlock.

Hardcoded class-names are basically the same as hardcoded colors.

The main problem is that the editor obviously stores information about layout, colors, typography etc. within the content itself.

That will always lead to confusion if some day another "theme" should be used and tries to show that content or if content should be exported etc.

All layout, color, typography information should be stored in some post_meta or similar - not in content itself.