It was definitely tactical to a very large degree. Different members of my extended family even voted for different parties in their geographies to keep the Tories out.
As for folk not reading the Labour manifesto, I am not convinced by that, since it was put under way more scrutiny than the Conservative one, which to be clear, costs 5 times as much!! They deliberately just didn’t show the numbers. People had to research it themselves.
“Conservative v Labour Manifesto” @EtharUK https://medium.com/@EtharUK/conservative-v-labour-manifesto-b1b870123f7f