Why did Parliament keep the tax on tea?

Parliament was trying to save the East India Tea Company from bankruptcy. Many in Parliament had financial interests in the company. The Tea Act would provide the company with a monopoly on the colonial tea industry. Parliament wanted to crack down on smugglers and also wanted to circumvent those who used boycotts to avoid British taxation--the tax would be paid as a duty whether or not the tea was consumed. Parliament viewed this action as a win-win; members of Parliament's financial interests were spared and Parliament was able to collect taxes from the colonies. Parliament stated that they had the right to institute this tax through the Declaratory Act of 1766 when they stated that Parliament had the right to institute taxes as it saw fit.
Parliament also viewed the Tea Act as a win for the colonists, as it made the tea from the East India Tea Company cheaper than smuggled tea even if one considered the tax. The colonists rebelled on principle--they did not like paying for the tea whether or not it was consumed. They also did not appreciate that this tax was passed without their consent and that Members of Parliament directly benefited from the monopoly. This led to the Boston Tea Party and the escalation of hostilities which would lead to the American Revolution.