Tags are not a replacement for folders, and the opposite is true too. A folder defines a directed graph. Combining tags loose the "directed" part. It may be go

Tags are not a replacement for folders, and the opposite is true too. A folder defines a directed graph. Combining tags loose the "directed" part. It may be good enough for some, but it's not the same and will fall short in some cases. This difference is the 1st point mentioned in the article. The article says that it's inflexible. In some cases yes, then use tags. In other cases, it will be exactly what's needed and tags will be cumbersome. The two other limitations (related to searching and sharing) are bogus IMHO. They're not limitation of a folder system, but maybe of some implementation.