It all started with Unconditionally: people didn't want a serious song, and they demanded Dark Horse.
The following singles didn't do so well, even if they were childish enough (Birthday) or catchy and accompanied by a funny video (This Is What We Do).
The Olympic song was snubbed, then she tried a mixture of serious and rhythmic, CTTR, which did good but not so good.
Kids... grew up, so she tried to conquer gays with a sexy pastiche, BonAppétit, by choosing a homofobic featured act.
All her subsequent choices (those two silly video) were completely out of contest, kids were lost (forever?), gays who love camp were bored, and the general public completely disinterested.
And, yes, short hair never pays (Nelly Furtado, Jessie J), when it's not a trade mark (Sinéad).
"Despair, regret, and tenderness is what I feel for you"