In real life that up to 25% of braking ability on the back on a motorcycle is still 25% braking ability and no matter what nonsense you have heard about that, you wouldn't get a racing bike past inspection with a disconnected or ineffective rear brake, no matter how little it might allegedly be used. On a motorcycle the weights are higher, the speeds are higher, the weight transference to the front is more noticeable as the front suspension weights up and the rear unloads under heavy braking, and in those circumstances the rear brake becomes less effective and can become a liability if mis handled. That's still no reason to be without it. On a race circuit everything is going in the same direction.
On real roads you are manoevreing, riding slowly, riding (hopefully feet-up) round obstacles, doing U turns (again hopefully feet up) avoiding oncoming road users. You may have to ride up an unmade road or across mud on the way to work or even get across an icy patch or snow . Engine braking or the back brake lightly applied is a lot more useful than the front in all these circumstances. With this background now look at what you're proposing with a rear brakeless bicycle.
The whole point is control. There's more to riding a bike than just not falling off. With a fixed wheel and front brake you can do all on a bicycle that's in the previous paragraph. With two brakes, mostly using the rear you can do the same. Your options are more restricted with just the front.
Legally, see what
@Ajax Bay posted above.
To claim that being unable to maintain your bike to the extent that the rear brake drags as a justification for disconnecting it is a bit feeble. Why not disconnect them both? No remote possibility of drag there. Still just as illegal. Or learn to set up your brakes correctly. No drag there either.
A strangely pointless question which with all your experience and knowledge you ought to be able to answer for yourself.