Why are predicates duplicated for subject -> object and object -> subject?

[jamesamcl]

For example there is a boundBy predicate as in promoter boundBy tf, and there is also a bindsTo predicate as in tf bindsTo promoter.

My concerns about this:

1. It doubles the number of triples (one binding relationship is two triples)
2. It allows the possibility of inconsistency where one is present and the other is not
3. It is not consistent (not every predicate is duplicated like this). For example, there is a consumedBy but not a consumes.

Can we simplify by settling on one of the two predicates in these cases?

[jamesamcl]

Granted that inverse predicates are a thing in RDF land. I guess I might have spent too much time working on SBOL. ;-)