@GasPanic
If the aspiration argument is correct, why don't people reject high income taxes on the rich, because surely they aspire to be earning that amount one day. But putting up income tax rates for "rich Tories" seems very popular amongst Labour circles (I guess the money to shovel towards Labours voting demographic has to come from somewhere).
Lots of people actually understand behaviour. They're not necessarily thinking of themselves. My estate will never be enough to be liable for IHT, my income isn't high enough to hit 45% (it's never even hit 40%!), but I have enough life experience to know that when a person thinks they're going to be liable for "too much" tax (in their opinion), they're going to take action to avoid it, so indirectly, detrimental to lots of lower income people because of less tax in the pot overall, so less to spend on public services etc.
I've known lots of people who've taken action to avoid high tax rates, i.e. shovelling money into pensions to avoid losing child benefit or avoid the punitive 62% tax rate on incomes over £100k, loads of people setting up trusts as part of will planning to avoid IHT, loads of part time people refusing to work extra shifts or take promotions because of the loss of benefits, back in Brown's day, huge numbers of people converting from sole trader self employment to limited companies to save tax, workers wanting to be classed as self employed instead of employed to save tax/nic., or even someone self employed buying a crew cab pick up truck instead of a car because of better tax relief - it's never ending! All because of a perception of unfairness. How about Lewis Hamiltion buying his plane via the Isle of Man to avoid paying VAT on it! How about pop stars, sports personalities, tv personalities etc living in tax havens to avoid paying UK income tax! When such people take action to reduce the tax they pay, it harms UK PLC overall!
So even "lower earning" people who aren't directly affected will be indirectly affected by less money in the pot overall.