Honestly, that is rather debatable. The lack of Leftovers recovery isn't much though, but defensive Pokemon may still stand. Hail isn't a common sight on the battlefield, really, because they suffer from too much compounded weakness to Fighting and Stealth Rock, which means Poliwrath can stop hail teams cold most of the time. Hail has numerous issues: Firstly, it has to rely on the mighty Snover. That is bad. When you're forced to rely on a mediocre Pokemon like the Mighty Snover, that's a big crutch. Also, very few can take advantage of hail, and those who can are usually Stealth Rock weak, racking up Stealth Rock damage too easily. The impact Hail is making on this meta is not much. Stallrein and Mandibuzz can be very annoying, and Rotom-F and Glaceon can be super powerful, but you must keep in mind that they are Stealth Rock weak and they have the mass weakness to Fighting, plus they are extremely dependent on the Mighty Snover to be successful. Hail is not that good of a weather and is typically not hard to counter. It's not ban worthy.