I think you put the cart before the horse, while as noted in the article, put blinders on to anything that doesn't fit your forgone conclusion.

In the immortal words of Tyler Durden, "sticking feathers up your butt does not make you a chicken." Calling yourself a Socialist Republic doesn't make you a socialist republic any more than calling yourself the Democratic People's Republic of Korea makes you a democratic republic.

How about OP's examples of Denmark, Norway and Sweden? Are they authoritarian? What about Austria, where since the new Republic started the socialists have either had majority control or been one of the top 3 parties. Vienna has had a socialist mayor since WWII. Do you define Austria as "authoritarian?"

What feature of socialist countries that does not exist in capitalist countries do you define as "authoritarian?"