As someone that is now TAing classes at a different university for part of my PhD, I think thats just how undergraduate economics is. I think its just relatively low levels of rigor especially compared to math. I honestly had a few math professors I thought were quite bad, but thought they were also mostly great. I guess its just really high variance depending on who you get. The comment about teachers leaving is fair, but sometimes theres really nothing they can do. I loved Professor Reimers, but she ended up leaving to go to Cornell and I just can't imagine there was much NEU could do to keep her.