Even though both sides of the bargain achieved something, the treaty became a point of controversy because it could be viewed as an agreement that favored the british, being that a lot of issues caused by them, such as wartime damages, illegal capture of american ships and conflicts with the indians caused by the british occupation. The british agreed with leaving said posts but only after one year and a half. In the treaty there was also a ton limit to the trade that americans could have, making profiting from the pelt trade almost impossible.
Also, the treaty was configured in a way that seemed to favor the Federalists to the detriment of the opposing party, the Jeffersonians (who where against the british, believing that Britain opposed the values of the American people, prefering to support France whenever international issues called for U.S. contribution), who rallied against Washington, Hamilton and Jay. The Federalists where in favor of the british, believing that going against the british in this matter could lead to war against them.
