This is one of my pet hates.
Unfortunately it is not just BMW drivers that are guilty of cutting the corner. 95% of all drivers do it regardless of make and model that they drive, and I love holding them and their insurers liable when they try to defend a claim made against them when they claim that they (the turning driver did nothing wrong
)
It is an unfortunate fact of life that many motorcyclists are also guilty of this.
The biggest problem though (apart from drivers being lazy and dangerous) is that most coppers of the current generation have no dea that an offence has been committed, or if they do, they are too bone idle to report the driver.
This is where central traffic islands help because it prevents much of this, but the council are not prepared to spend the money even though it will save them millions in the long term.