Practitioners after attaining Moksh, the state of no pain or pleasure, for the advantages of others
created some characters of relevance to describe the essence of their spiritual journey (because that journey cannot be narrated by physical means; thus described using names of popular places and persons). For example, to make a
beginner understand, a teacher teaches A for apple, though he knows A is not an apple. The followers according to their convenience took the symbolic meaning of characters; not the relevance. Epics emerged and stories flourished
resulting in prominence of physical names and places as the objects of worship.
The Sanskrit root for Krishna is 'karsh' which means 'to pull', 'to attract'. The
name Radha is derived from the root word 'aradhana' - meaning worship. The person who absolutely excels in worshiping Krishna is called Radhika (anayaradhito).
Srimad Bhagavad: Tenth Skandh, Chapter 30, Verse 28
anayaradhito nunam bhagavan harir isvarah
yan no vihaya govindah prito yam anayad rahah
She, a particular gopi, has excelled absolutely in worshiping the supreme controller, Lord Govinda,
and He was so pleased with Her that He abandoned the rest of us and brought Her to a secluded place (so called nirvana).
This clearly conveys that each one of us may become Radha provided we too practice aradhana
absolutely. We have divided ourselves by gender, but for 'karsh' to 'aradhana' there is no gender; for that matter all of us are gopis. When Meera was denied entry to an Ashram in Vrindavan stating only purush may enter; she said,
"she knew of one and only Purush, wherefrom another purush has emerged".