There's little evidence that labour laws cause unemployment. This meta-analysis (https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2705499) points out that minimum wage laws have little to no effect. Wider analyses (http://onlinelibrary.wiley.com/doi/10.1111/j.1564-913X.2014....) also seem to conclude that labour rights have little effect ton employment rates.
Is this (https://saylordotorg.github.io/text_principles-of-economics-...) hard to understand?
Or maybe you want something more rigorous: https://mises.org/library/theory-idle-resources-0
https://en.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_fi...
Remember that these mighty legislators didn't prevent these deaths also, they only acted after the fact.
Stop being a Brazilian advocating for liberalism because you like to use the US as a role model... I know too many of you back there and most are completely ignorant to the problems that arises from that, you don't have a clue what you are talking about.
I could spend a lot of time here elaborating a reform proposal, but that would be pointless, right? You don't have the power to do the reform even if you get convinced.
It is better to just come here and state the obvious, hoping that other commenters may be interested in learning some basic economics -- not of Keynes variety, which is a separate discipline -- and accept that labour laws are mostly bad.
After we get more people convinced of it we can elaborate a politically feasible reform.