Terrible, vile things tankards. Every pub I've ever used served beer in perfectly good glasses. Anyone who had their own tankard hanging up behind the bar I'd mark down as a complete tosspot. I'd like to be more liberal and understanding about tankards but they're the worst kind of snobbery in a portable form. Everything that's wrong with folk, superficial, ahistorical, superior, backward looking, twerpery. In short, ridiculous.
Thanks to the OP for the opportunity to sound off on the subject.