Banjomad: the idea of the Poll Tax was not to subsidise the wealthy, but to equalise the burden of cost. A wealthy person does not create more rubbish than a poor one, nor visit the library more often, nor require a greater standard of policing (and if they do they pay for it!), so the intention was for local taxes to be based on the number of people in a house, rather than the house's value.
The idea that the rich should pay more because they have more would see multi-tier pricing for bus tickets by the same 'logic'.
With the Poll Tax, the really poor could get subsidies and exemptions. It was the 'working classes' who were hit by the novel idea that everybody should pay at the same rate for the same services.

Nigel