Because the world has changed. We're now competing in a global economy. We're in a technological revolution. It's cheaper to make stuff in China/Japan and ship it here. Western economies in general are having to adapt to a new world where we're not the richest/wealthiest countries anymore - the world's wealth is moving to the previously underdeveloped countries. That means an inevitable reduction in living standards in the West. The UK is already living well beyond its means and having to borrow huge sums of money to maintain our illusion of wealth. We simply can't afford to stand still and carry on doing things the way they were always done. We have to change and adapt. After all it's a mere accident of birth that we're all here in the UK and enjoying a relatively good standard of living compared with many millions on the planet - as globalisation continues, we have to accept that living standards of people in underdeveloped countries will rise and ours will fall as a consequence. It's all now about how we adapt to this brave new world and those trying desperately to cling to outdated working practices and a sense of self entitlement are divorced from reality. Unless you want protectionism, closed borders, etc., the genie is out of the bottle and adaptations are necessary which some people won't like. I don't agree "it benefits no one" - we are all enjoying much cheaper "stuff" due to cheap foreign labour, cheap fuel, etc - if we didn't have the race to the bottom and globalisation, yes, we may have more well paid jobs, but the price of "stuff" would be an awful lot higher, meaning we'd have less money or less stuff. You can't just pick on things in isolation when you're a small cog in the big wheel of globalisation and international trade.
I never agreed with getting rid of protectionism in the first place. The French have the right idea.