Then the important question is this: When you say better, better in what sense? Beyond a certain point, people have different criteria and your better and my better start to diverge.
In Scheme, traditionally such matter has been settled by "agreed to disagree"---instead of choosing one, the spec just leave it unspecified. But R6RS had a goal to allow portable libraries, so it had to choose one; for modules, it is better to have lesser but one module system, rather than having multiple ("better" in various regards) or than having none.
In Arc, ultimately it's up to pg.
[Edit: To be more PC, R6RS module is 'less agreed'. I do understand it is better in its design criteria.]
Good question. I'm sort of inspired by PG's thoughts about object-oriented programming, that it would be better if they offered the features a la carte rather that packaging them up into objects.