Adam Smith pointed out two and a half centuries ago that this is a hollow protection at best, and a deliberate falsehood at worst, given the general reliance the employed still has on his or her (considerably more powerful) employer, and the inequality of bargaining power between employers and the generally far larger pool of employable persons. Time has not served to significantly lessen the viability of his point.
Adam Smith knew as well as anyone that all markets are subject to market forces.
When there is a surplus of labour, then the buyer (employer) will have more power. When there is a deficit of labour the seller (employee) will have more power. Right now, there is a surplus of labour at the uneducated, unskilled end (some blame immigration, I blame our "one size fits all" education system) and a huge deficit at the trained and/or highly educated and capable end.
So factory labourers probably have little in the way of power (not sure how much an untrained/unskilled labourer should have), but at the other end of the scale, the opposite is true.
What has proven to be an ameliorating influence has been the beneficial effect of labour laws, worker protection measures, welfare systems and social security nets on the ability of the average worker to stand up to his or her employer. All of which were (to a huge degree) driven by pressure from unions (or parties founded by and beholden to unions, like Labour) - the great advances in the ability of the average Joe to stand up to unfair employment practices came not out of the goodness of the mill-owners' hearts, but out of their sweating fear of collective violence, political change or economic disruption caused by unionized workers standing up for what they perceived to be their rights in an increasingly turbulent world during the late 19th and early 20th centuries.
Those changes can't come about in a vacuum. There has to be a general consensus to change laws, otherwise the government trying to change those laws doesn't last long enough to implement them.
Society as a whole has discovered that there is a "most productive" equilibrium when balancing treatment of staff vs time/money invested. These laws have simply matched those changes in opinion.
And if you're going to use mills as an example of poor treatment of workers, then I suggest you dig a little deeper into history. Whilst conditions were terrible by today's standards, those who worked in mills were the envy of most other workers as the alternative was usually back-breaking farm work (or no work). Conditions changed as they do over time, but even the worst mills were often a better place to work in than the alternative.
The past three decades have seen a slow erosion of quite a few of those hard-won rights, which was accompanied by the decline in the unionization of British workers in general. Now, the unions' demise was (I think) their own fault given the way they overreached and (grossly) overplayed their hand in the 1960's and 1970's - but it is no coincidence that their decline has accompanied a general shift in power back towards employers at the expense of the average worker. And, given that we're now entering an age where fewer and fewer 'average Joes' are likely to find employment as fulfilling or remunerative as their considerably less-educated and qualified forebears were able to find (with automation and the intensive shift towards knowledge-based industries only advancing at an ever-faster pace), that trend is likely to be reversed anytime soon. Which brings with it a looming danger of employees losing even more of their hard-won rights relative to their employers even as social services are cut, welfare systems are privatized or (alternatively) demonized and a series of escaped goats are built up to distract them from the loss of their negotiating power and worth relative to that of their employers.
You're right that unions overplayed their hands, the problem is that so many of them are still living in the past and are still overplaying them now. There is little public sympathy for unions that inconvenience them, and so they will find it increasingly difficult to use their disgusting ransom tactics to hold employers over a barrel.
Again, market forces rule. Those with rare skills are not finding those problems.
I'm not sure where this idea that workers have a certain level of worth regardless of education and/or ability comes from. As with any market, rare and desirable assets will have value, commodities that are easily found/replaced do not. Society is changing, and people need to change with it. There is a problem with our education system, it doesn't properly prepare people for life outside of school and it really needs to. Good teachers can spot those not suited to academia - those people should be learning trades that they can use when leaving school, not being prepped for college where they'll take any old course because that's what the government thinks they should do. Many are even shepherded into university to waste another 3 years on subjects that will do them no good in the longer term.
But school issues aside, there are plenty of opportunities to expand one's knowledge - I have a couple of employees working for me who changed their careers later in life and they're being well rewarded for it.
Long story short, that isn't as much of a protection as you think it is - and will likely become even less of a protection over time, if present trends continue. That is not a good reason to give up what few powers unionized workers can still wield.
It is if you're really good at what you do or are particularly hard working.
Those employees that have left us over the past decade or so were mainly ones that we were not so fussed about losing. We've done everything in our power to keep and progress the good ones because they hold extra value to us. I don't think my company is unique, or even rare in that regard.
