I hope you read the whole article, because it's a balanced well-argued piece.
More generally, the English language evolves continuously and any publication worth its salt, which wishes to retain and gain readers, especially internationally, must adapt to changes in the demographic and the ways its readership uses the language. It may not necessarily be the way you as an individual use language, of course.
I'm sure we can agree - whatever your political views - that The Guardian is also a 'distinguished journal'. Here are just a few recent headlines from it - there are plenty more:
DeploraBall: Trump lovers and haters clash at Washington DC event
Nothing else matters: Metallica's haters never really understood the band
Bring on the haters: the show that’s getting laughs out of Islamophobia
Internet trolls beware – these rules will separate the haters from the hapless
Paul Feig hits back at Twitter 'haters' trolling Ghostbusters' Leslie Jones
To all you Renoir haters: he does not 'suck at painting'
And some from the Daily Telegraph:
Why Hollywood haters will soon learn to love Trump
A new reason Marmite haters could learn to love it: study finds the spread can be used to make beer
Sorry Alberto Salazar, but the haters will carry on hating
Like it or not - and personally I'm in the 'not' camp - the word 'hater' is insinuating itself into everyday language and that current usage is already reflected in Collins English Dictionary:
(informal, mainly US & Canadian) a grudging or spiteful person, esp one who disparages others: Don't let the haters get you down