Final answer:
Colonists were angered by the Sugar Act's implications on their rights, such as 'taxation without representation' and the loss of local judicial control, rather than the economic impact of the tax itself.
Step-by-step explanation:
The colonists' real anger about the Sugar Act of 1764 was not simply about the economic burden of the tax on sugar but rather about the broader implications the Act had on their rights and the way the British government was beginning to exert control over the colonies. The Act lowered the duty on imported sugar but ended the once profitable sugar and slave trade with the West Indies. It also enforced stricter measures to control smuggling and judicial processes that bypassed the local juries in favor of Admiralty Courts, which did not use juries.
This invoked a sense of lost liberties among the colonists, notably the right to be tried by a jury of their peers and the right to levy their own taxes, a principle that James Otis and others believed to be inherent to British subjects. The anger was essentially rooted in the concept of 'taxation without representation' and an affront to self-governance.