Unskilled Racer almost Becoming Dead Racer [Video]
Swiping all over the width of a road will have you pulled over in case a cop sees you and you'll be lucky to get away with a warning, only.
The other reason because you need to learn to stay in your lane is crashing. Under- and over-steering can easily send the bike off the road or worse, head-on into an incoming vehicle. Both these are extremely bad, with running off the asphalt being more hazardous only on mountain roads, with huge falls beyond the guardrail.
But a head-on encounter with a car, some speed added, is one of the worst things which might happen to a rider, resulting in horrible mutilations, amputations, paralysis and death. Plus property damage and state expenses. So ride safe, and learn how to keep in your lane. Roads are no MotoGP track. Seriously.