Agree.... 2 stroke engines in dirt bikes are designed more for pegging the throttle and power shifting which is great for racing and track use. Not so much for fuel economy... It will work on the road with different tires and sprockets though there is no question. I have a 1990 RM250 that I have taken on a 35MPH street in off road form. At 35MPH the power valve remained closed so there was a little bit of surging which wasn't bad but it was annoying.
Note the road was owned by the off road park and does allow unlicensed vehicles to travel on it to get to the other parking lot. No laws were broken.
I imagine if I put a smaller rear sprocket it would correct the surging but I didn't buy it to be on the street
Be prepared to spend some time and money converting it to be street legal. You will need a DOT approved headlight, tail light, turn signals, license plate mount and light, speedo, odo, kill switch and tires. You will also need to think about sprockets, key and if it isn't equipped already you will need to get a stator that has a second circuit for charging a battery to run all the street junk.