That’s the point of having both seasonal and evergreen characters. If you don’t want to play seasons, then don’t.
Seasons are necessary to keep the game fresher for longer. D3 seasons were excellent, and the grind moved from leveling into gear acquisition and gRift pushing. It was a really cool model, and I’m sure it will be more of the same once they find the balance, if they haven’t already in s1.
Yep, the loot is terrible. The legendaries are strictly worse than the rares after you have a healthy inventory of aspects. I’m only hunting uniques now, as the rares have 800 million affixes and never remotely close to what is needed.