Not so much a taboo for the public as a taboo for special interest group money. But it just needs a campaign to show that advertizing without tax makes taxes invisible, because you just pay it and gripe after, vs tax included and you change your purchase decision because it is too much money.
Every jurisdiction I've been in that charges a consumption tax requires it be shown on the receipt, regardless of whether it was advertised as inc or ex tax.
Right, and that is the argument used against free tax returns in the US. They want taxes to be painful enough so that filing your taxes makes you think about them (and hence you would support the party that lowers taxes etc.)
Every jurisdiction I've been in that charges a consumption tax requires it be shown on the receipt, regardless of whether it was advertised as inc or ex tax.