“If you pay tax, you should be able to vote.”
So conversely, if you don’t pay tax, you should not be able to vote? So that rules out the unemployed and those living on low pay.
“Again, how do people over the age of retirement contribute to society apart from give their very educated, stern opinions? And how does this contribute more than someone from the age of 16, who works and pays tax?”
People over retirement age very often undertake voluntary work. They also very often have retirement incomes far in excess of those of younger people and so pay far more in taxes (so your earlier point makes them eligible to vote).
“…they've had their say, now time to relax and leave the voting to those who it'll effect.”
So government does not affect older people? The tax they pay and the services they use? And when do you make the cut-off date for voting? State pension age (when, on average, people will live for getting on for another fifteen to twenty years - about a quarter of their lives)?
I believe you need to re-think your strategy, spathi.