People saying that they don't like to use the name because of its association with Adam Lambert makes no sense. People don't quit using names like Ted, Jason, Freddy, or John, even though they all belong to literal serial killers.
During Henry VII's reign in England one of the more serious pretenders to the throne was a Lambert Simnel who claimed to be the Earl of Warwick in 1487.
Lambert Wilson is a popular French actor who starred in the film "Of Gods and Men" but is best known in the states for his role as the Merovingian in the Matrix films.