Absolutely correct. What people forget is that the Mississippi used to have flood plains all along its path. When there was heavy rain anywhere along its course, the waters would raise and it would overflow its banks depositing rich soil and silt all along the way. Now, we've replaced the flood plains with housing developments and mini-malls.
That's not so much the case in the Baton Rouge area because of the protected Atchafalaya Basin and the big lock between it and the Mississippi. In other parts of the Midwest, though, you're absolutely right. Wetlands are for water, not for strip malls, oil pipelines or fracking sites.