Lastly, tea — unless one is drinking it in the Russian style —
should be drunk without sugar.
I know very well that I am in a minority here.
But still, how can you call yourself a true tealover if you destroy the flavour of your tea by putting sugar in it?
It would be equally reasonable to put in pepper or salt.
Tea is meant to be bitter, just as beer is meant to be bitter.
If you sweeten it, you are no longer tasting the tea,
you are merely tasting the sugar;
you could make a very similar drink by dissolving sugar in plain hot water.

Some people would answer that they don’t like tea in itself,
that they only drink it in order to be warmed and stimulated,
and they need sugar to take the taste away.
To those misguided people I would say:
Try drinking tea without sugar for, say, a fortnight and it is very unlikely that you will ever want to ruin your tea by sweetening it again.

George Orwell-
The Collected Essays, Journalism and Letters 194-1945
(Later Published in the London Evening Standard, 12 January 1946)

So very, very true.