Personally, I don't "hate" the current terrain generation. It's ok. But I do like the terrain of the old early beta versions. The terrain was smooth and clean, lots of variety between the biomes, and beaches were very nice. Plus, the ocean terrain looked a lot nicer compared to what we have today (smoothed out, nicer looking terrain composed of dirt, compared to today's ocean terrain, which is extremely hilly, and composed of blotches of dirt/sand/clay that hurt your eyes to look at).
To be honest, I'd love to see something like in "Better World Generation 4"s default terrain. That's how it should look. Keeps the vanilla biomes, but adds lots of variety to the land, and makes everything look nice and neat. Though, I probably won't lose any sleep over it if Mojang decides never to change the terrain, haha.