I still don't see what the problem is. Their customers want USDT. They buy USDT so their customers can access it. Looking around on their site, it looks like they support USD alongside USDT, so it's not like they're strongarming their customers into using USDT. Calling that shady is like calling a stock broker shady because they're the largest buyers of [insert shady/overhyped company here].

They are tethers largest customer because they're the largest exchange and tether is the largest stablecoin. Stablecoins in general were created because offshore exchanges had trouble dealing with traditional banks since the whole point of being offshore is not following US regulations.