This perfectly encapsulates the problem on the left, I think. People don't vote Tory because they "don't care about public services". I care about them, but Labour's record is a bit grim and the solution of throwing money at the problem whilst simultaneously working out how you're going to fund it isn't exactly a winner. The shadow education secretary was on Daily Politics yesterday and he couldn't explain how any of their proposals, however reasonable they may sound, were going to be funded.
Labour did this from 2002, running a significant budget deficit for current expenditure and borrowing to plug the gap. It's a bit cruel to offer people public services that aren't sustainable from a funding perspective, because at some point they're going to have to be taken away again.
Tax increases never yield commensurate returns. You could try, but the likelihood is that you're almost certainly going to have divert money from other departments to meet Labour's proposed spending increases. Which is perfectly reasonable as an approach, but when you get into the detail of it you're in a bit of bother trying to work out where it's coming from. The three biggest areas of government spending are health (Jeremy wants to increase funding), pensions (Jeremy wants to keep the triple lock), and welfare (Jeremy wants to significantly increase its scope).
So after he's implemented significant increases in funding for the three largest departments, where do you find the money to increase the education budget to the extent you need to for his policies? He wants to remove tuition fees as well, which would be another heavy increase in cost (excluding any social impacts like reducing access for poorer students).
It just doesn't add up, in any way whatsoever. The Tories are hardily world class economists, but there's not exactly a choice to make between the two approaches.