You are correct that you would NOT want to use a "car oil" with "Energy Conserving" on the API label. Those have friction modifiers and should NOT be used in bikes. The can mess up the wet clutch in a bike. Heavy Duty "Diesel" oils have and are VERY successfully used in all kinds of bike
applications including racing bikes. Several of them are now
Rated JASO "MA" (i.e. specifically for motorcycle applications)
Rotella T-6, and the 15W-40 "diesel" oils (generally called HDEO's on here) work very well in motorcycles.
SOME "car oils", mainly in 10W-40 and 20W-50 also can be used in bikes but won't have as high a quality additive package as the HDEO, particularly in the anti-wear department. Those "car oils" are NOT "Energy Conserving" and are generally compatible with bike wet clutches.
There is nothing "wrong" with bike specific oils, but the price is much higher than oils like Chevron Delo 400, Rotella T, and Mobil Delvac, etc.