First, let's pretend this idea that Labour's policies will take us back to the 1970s is accurate.
1) In the 70s, the Tories broadly agreed with nationalised rail, energy and postal services, free higher education, higher taxes on the rich (way higher than Labour are proposing now) and on corporations etc.
2) The 70s actually were a pretty ok time for most of the population with fewer unemployed, many fewer underemployed, many more in secure work, affordable homes*, low homelessness, no need for foodbanks etc etc
3) And this is the big one: the politicians and media goons who are saying this want us to be out of the EU, they're small-state, fox-blood-hungry, want low tax and are anti-immigration. I mean, is getting dressed up in smart red jackets and hats with expensive horses and dogs, tooting horns and chasing foxes their idea of how to behave in the 21st century?! They want take us back to the 1800s if not earlier.
*Example: my Dad worked in a long-gone UK commercial vehicle factory and with two kids and as the sole bread-winner he could afford a mortgage on a 3-bedroom house with a garden, take us on holiday every year and buy us Christmas and birthday presents.
Labour's policies for this election are a response to the mess created by Thatcherite policies which have brought huge income inequality, completely unaffordable housing, increased homelessness and class sizes, weakened the NHS, increased transport and energy costs, brought us insecure jobs with the longest wage stagnation since the Napoleonic wars, taken away UK industry...I could go on. And what's more, they are at least as carefully-costed as Tory policies - although don't expect anyone in the media to push the Tories on how they'll pay for more tax cuts for their mates because their mates in the media will be those benefiting.