That's not why they get most of their media attention tho. Selena gets most of it by being Justin's girlfriend and Demi gets most of it by going to rehab as a Disney star and being next to Britney at the judging table on X-Factor. Not because of things they "truly" work hard for.
X-factor is something Demi works hard for, it's her job and is a valid thing to get media attention for while being justin bieber's girlfriend is not a job or something valid to deserve media attention from.
Selena because of Justin obviously.
Demi used to get media attention because of rehab but not anymore. Now mainly because of X Factor, but of course those stans would come up with Britney
this is a part of her work.
They both get/got media attention for the wrong reasons.