Adrian Auer-Hudson, MIMIS wrote:
IIRC, Moorgate was extensively refurbished in the late 1970s. It
seems a waste now. The LU terminating platforms have not seen much
use.

Not entirely true. They don't see much in the way of scheduled use but they
tend to get used very regularly during the peak hours for turning back
trains from any of the three lines that they serve, in order to better
regulate services - for example, to get late incoming Met services back on
diagram, rather than running through to Aldgate and causing knock-on delays.
In the (regular) event of signal failure in the Aldgate area they are used
for turning back all Circle and H&C services, in that event Met line trains
(other than those in the section between Baker Street and Moorgate) tend to
get turned back at Baker Street.