Now there's a premise. Before looking into this, we'd have to ask if 1. The Anaconda Plan was adopted, and 2. its execution was what won the war for the Union.

I'd contend against both assertions. Winfield Scott was removed from his official position before the war had gotten into full swing, after all; his successor, George B. McClellan, had radically different ideas about how to prosecute the war. Whereas Scott wanted to use a blockade to turn internal pressure against the Confederacy, McClellan wanted to advance on Richmond via the Tidewater rivers to force the Confederates off their most important base of operations; this would be executed in conjunction with coordinated advances on Corinth Mississippi and Chattanooga Tennessee to deny the Confederates use of their main lateral rail lines. McClellan's successors in command of the Army of the Potomac, such as Burnside and Hooker, similarly sought to capture Richmond, even when Lee's army was campaigning in Pennsylvania in the latter case. Throughout the war, the largest field army of the US remained in the east, and undertook near continuous offensives against the Confederacy's main army. While the Union did establish control over the Mississippi during the course of the war, they did not use Scott's proposed method of amphibious forces moving directly down the river. The actually proposed a few different methods at different time; describing them as part of a concrete plan we can hang victory on his charitable at best.

This was the appropriate course of action, especially following the Emancipation Proclamation, which ran counter to Winfield Scott's conception of the struggle and its political causes. Objectives like the complete conquest of the hostile state, and so much more the utter destruction of their social system, demand the enemy not have the ability to resist; their will can't be exhausted until victory is no longer possible. This requires the destruction of the enemy's fighting forces, as well as the occupation of their territory to prevent them from raising new forces. Winfield Scott's conception of using the economic measure of blockade as the primary offensive instrument in lieu of a military strategy of annihilation would be theoretically sound, but the blockade not only preexisted the various proposals that eventually got labeled as the Anaconda Plan, but it also was not effective, in either the legal sense (preventing shipments into the south) or in the strategic sense (inciting public opposition to end the war).

The war was decided when this army was surrounded and captured in the Appomattox campaign; the surrender of the major Confederate armies, rather than civilian pressure, ended the war. Especially in the face of destructive Union policy in the south, public morale remained largely in favor of the war; the North went from being a conquering foreign people to a race of devils delighting in destruction. While there were initial dips in morale when Union armies campaigned through the Southern interior, public mood quickly recovered. It's really fascinating; in the Shenandoah, repeated ravagings of the territory seemed to only inflame resistance further, with one interesting letter recounting with pride the blow struck by the teenagers and seniors of the Virginia reserves against a mixed brigade of black and white regiments. The will continue the struggle was there, but once Lee's army was driven from its base in Richmond, surrounded, and captured, the South no longer had the strength to fight back, and the surrender of the other Confederate armies soon followed.

With all this in mind, adulation for the Anaconda plan seems very much misplaced.