Why companies should hire Juniors in IT?

Great points! As a not-so-recent Jr. Dev, self-taught, who sought their first tech job I wish more companies were open to new comers to the field. From my experience in the job hunt, and this is anecdotal, my biggest hurdle was company HR/recruiters. I felt they were seeking to check off requirements on a job posting, rather than understand if an applicant had potential for an entry-level position. It's not their fault, their job is to fill a position with the most qualified, but I found they weren't necessarily asking the correct questions to assess ability. Which led to generic "not enough experience" rejections.

For example, an HR would ask me "Why do you love programming in JavaScript?", while a lead dev would ask "What have you done with JavaScript?".

I do wonder if this is a similar experience for some breaking into the programming world? They get shot down before they can demonstrate worth.

Interviewing with the lead devs taught me to approach the job hunt from a new angle, by talking to local developers and startups about opportunities. I would build projects and have them as talking points when networking. It aided in landing some internship offers and full-time work, and skipping the dreaded recruiter process.

On a different note, what are your thoughts on when is it appropriate to hire a junior dev vs senior? While Junior devs can be good for long-term investment, there is some risk to hiring new comers, especially if there isn't an environment to properly mentor them. Also, do you have strategies for Jr. devs in finding work?

I think there is much truth in the article. Hiring Junior Devs can have tremendous value in the long term.
Also, to be honest, the term "Junior Dev" is only a job title and says very less about the actual person/ambitions/skills behind it.