Irene Adler, why do continuers make a villainess out of her?

How come later writers consistently make a villainess of poor Ms Adler. In A Scandal in Bohemia, which I believe is Doyle's only use of the character, she is the intended victim of a burglary Holmes is hired to carry out. She's not a criminal, she is not a blackmailer (the aristocrat, whom Holmes dislikes, is paranoid), she is an accomplished opera star who is both clever, decent, and has a sense of humor.

Later writers apparently want to make her a thief or, worse (a fabulous lesbian dominatrix in Sherlock).

because many of these 'continuers' are NOT Conan Doyle and have little of his imagination nor latent detective skills. that is why many (most?) pastiches using the characters of Holmes and Watson et al are really not Holmes stories at all, just flavored formula with a new gimmick.
this is much the same complaint i have with 'Elementary', a show i actually like somewhat, with the caveat that although it is as good as any other detective series currently on TV it is decidedly NOT Holmes (imnsho).

it takes more than just replacing the name Sam Spade with the name Sherlock Holmes.