Is The Merchant's Tale Anti Idealistic?

Yes, it is.......

The tale "quites" the Clerk's idealism with cynicism. The Clerk had an ideal view of the past and an ironic view of present realities; the Merchant has contempt for ideals and a bitter view of realities. For the Clerk, the world may be in decline, but for the Merchant all is leveled to a nihilistic worldview. He's even ready to sacrifice the fiction of his own dignity.