Original plan was to create funds to would buy up more than the majority of the stock of all major companies in Sweden, all controlled by the labour unions. That would have been de facto socialism. Why? Because the labour unions was married with the political power, the Social democrats. Biggest labour union of them all, LO, controlled Social democrats with funding and forced memberships.
All political power and economic power in one entity would have been very dangerous.
After controlling the major companies in Sweden, they would have of course continued with the non-public companies, because the main goal of Löntagarfonder was to create equal salaries between high profit companies and low profit companies.
Taxing profits in moderation is not breach against democratic principles, but using the companies own money to take ownership over it is.
Right to run your own company was established already in 1864 in Sweden. Löntagarfonder was a direct opposition to that.
https://en.wikipedia.org/wiki/Decree_of_Extended_Freedom_of_...
There is nothing wrong with worker ownership if the workers create it by themselves, taking other peoples work is not okay.