"Talking of tomatoes, they come in tins, not bloody cans.

Oh, and its aluminIUm."

'Can' is generic, no matter what the material is: those containers have not been made of tin for many years.... same with TIN foil, which is now aluminum foil. (and you may remain stubborn about your cherished pronunciation & spelling, but world-wide you are outnumbered.

http://www.worldwidewords.org/articles/aluminium.htm

All those extra letters (especially 'u') use up SO much ink over the years, and take extra time to type. we poor colonists prefer to save whenever possible. ;>)