In my opinion, at least its more likely that LSD being sold would be real LSD. The idea was that NBOME was easily sold as LSD and was very profitable, and legal, thus far easier to obtain. But only time will tell the trends. For now, it will still run around the streets for a while.
It has not worked that way for methylone in the United States, which has been Schedule I for a while and a MDMA substitute in "molly" all the same.
Ballz_Trippington: Not always, but in general, I see more focus in US law enforcement focus on who *deals* the drugs. My guess is that the specific scheduling is most targeted particularly at those who order chemicals from uncontrolled places (such as China) and either sell them over the Internet, or lay them on blotter and sell them as fake LSD. Users do get arrested too, but I don't see them targeted as much.
Again, as per methylone above and many other scenarios, this does not work too well as far as preventing drugs from getting around. It does a good job of keeping our prisons full, though. The prison industry has been a cushy job to be in if you were in the US.
(To be honest I'm expecting that to change. We no longer can afford our massive penal scheme, and citizens are slowly pushing back against things that have kept prisons full -- for instance, marijuana criminalization and related, three strike / mandatory minimum laws, etc. But it will be a while before synthetic drug policy reform happens. As the most dangerous synthetics in the US, in terms of # of deaths per year, are synthetic "legal" opioids like Oxycontin -- I expect something to happen there, too, somehow, eventually. We live in curious times.).
As to why those three, and not a blanket NBOMe ban? No idea. I guess maybe the idea would be to keep the other chemicals available for use in actual scientific research.