Depends on who you ask.
If you ask an aerobatic pilot he will say it's 5 hours too much.
If you ask somebody who goes places, he will probably say it's not enough.
The basic problem is that if you did more than the very minimum, for example you taught people to really fly (and navigate) safely in IMC, and fly some basic instrument approach (say an SRA) then you would be accused of leading pilots to their deaths etc when they fly into hills. The fact that many more lives would be saved will be disregarded because one doesn't get to hear about those.
And the proposal will be criticised by the old guard as introducing a back door quasi IR which is illegal to use anyway.
So, the minimal instrument training is consistent with the basic PPL privileges that you must remain VMC and if you enter IMC you must get out of it fast.
I think it's cynical but I also see it can never be changed - until there is a big overhaul of flying and somebody decides to train people to have some significant mission capability, beyond flying a circuit.
If I was teaching somebody I care about to fly I would make sure they can do everything in IMC (on autopilot) and land with an ILS or an SRA. Before they go solo.