Have conditions as separate entity will help to reuse condition across Rules. Currently its more of rewriting same across onn Rules( which can help to trigger diffrent tags on same set to cinditions).
I work around this by writing a "Custom Code" Data element, and use that data element as a condition. This creates a condition that can be reused. But yes, I think a "Conditions" feature could be nice so Conditions could be written in a simpler way.