Can I confess I've never quite wrapped my head around the application of the 'inhibit' line in this?

If a write cycle is just a read cycle with a) a reversed polarity and b) you don't care about the contents of the sense line - I don't get why current coincidence is sufficient during the read cycle, but not during the write cycle?

Every description of this I've ever read, sound like inhibit and current coincidence solve the same problem - but have never left me clear on why we need to solve it twice.