Flying an approach in solid VMC without the equipment needed to fly the published missed is like flying high on drugs? Seriously? IMO that's a false equality. You could just as well say that going 5 mph over the speed limit or finishing passing someone on a two-lane highway past the double yellow line is like driving/flying high on drugs. One can, and is likely to, kill you or innocent people. The other may or may not be dangerous, depending on the circumstances.
I generally obey the law and would never counsel someone to break a law -- pretty much any law. But I don't pretend that all violations of the law are equally serious. I would answer the OP's question much like everyone else has: it's not legal, but I won't tell you you're likely to get busted. It's on you, like flying IFR when you're not legally current or rated. If conditions are solid VMC, it's still illegal but you're unlikely to get into trouble for it - unless something else goes wrong. And it's NOT like flying stoned, or deliberately flying into IMC in busy airspace without a clearance, which makes you a blind menace and for which I wouldn't hesitate to turn someone in.
Flying a
simulated IFR approach in solid VMC is of course OK, legal, and recommended for rusty or new pilots. Flying any IFR approach, regardless of weather, without the equipment required for that approach, is illegal and potentially dangerous. Yes, you can get away with a lot of illegal activity with no harm done, but the law is there to create bright lines.
I agree that all of us cross the line sometimes -- going slightly over the speed limit on the highway comes to mind -- and we do so while weighing the consequences: increased risk of an accident and/or getting caught/fined. Similarly for many other laws and legal limits, aviation included.
So each of us has their own personal bright line: for me one line would be getting an IFR clearance without the requisite (and properly functioning) equipment. Yes, in solid VMC you are probably not going to get into trouble, but the problem is the slippery slope that none of us humans is immune to. So today it's solid VMC, tomorrow just plain VMC, and next week it might be marginal VMC, until we start going through clouds. After all, we are on an IFR clearance, right?
Then we might end up NORDO in that situation, and if we don't have the right equipment, we are up the creek.
So once you start flying around illegally, it will lead you to taking higher and higher risk, to yourself and others. Perhaps not identical to flying or driving while intoxicated, but similar in the attitude of disregard for laws, safety, and others around you.