My and your definition shouldn't matter, if we follow the original thread. What you were talking about is how people self identify. What you're describing are now markers of being middle class, but there were people who didn't fit that strict criteria that still identified as middle class half a century ago.
Is it your view that majority of the population identified as working class 50 years ago...but they generally voted against the party that identified with their class? People's socioeconomic status can be defined by absolute measures but most people have defined their social class on relative measures.
My point wasn't that's everything is nuanced, but rather the nuances you're skipping over are so significant that they should be considered something beyond that. It's necesarry to ignore some of the nuances in generalised discussions, but that's when they're small and insignificant.
Parties have won power all across the world this century, and in the previous century in this country, while putting themselves forward as a party for a particular class. And people outside of that class voted for them. What you're saying as an absolute statement needs something a bit more substantive to justify it, in that context.
Is it the case that the modern British voter is completely different to those voters? Maybe. But what explains the London Labour vote? They didn't think the Labour Party had specific policies for them, and for the class most of them are a part of. Many considered it an aspirational vote, just of a different kind. They didn't feel the focus was somehow exclusionary towards them.