One of the problems with the TA is when you look at their annual budget (£350-£400m 'ish) against the actual numbers who deploy each year (~2000) in support of ongoing operations it gives the impression of being a very expensive organisation (all things are relative I guess). Having a huge TA was great for acting as the 2nd / 3rd etc line of defence when it was 'all hands to the pumps' to protect Fortress Britain. Some key trades remain essential - medics, siggies, drivers - but to cease training across the board does seem excessive. Medical care to operations would grind to a halt without the TA/NHS to support it.
It will, of course, make CGS look like a Saint at the next planning round having made this sacrifice. The pressure will be on for CNS and CAS to follow. No guesses what they'll be expected to provide ....