No offense intended, but you obviously haven't been paying much attention the last thirty years.
And apparently he's never heard her sing.
She's carried herself head and shoulders above the entertainment crowd, never seizing the notoriety of her husband's murder to promote herself or some idiotic cause celebre, that I know of. She has remained devoted the memory of John Lennon.
All the Beatles, regardless of their politics, have been nearly models of deference, humility and good manners, by any standards, especially today's.