Why is terrain water so ugly?
Why can’t I get it to smoothly transition from water to land?
Sadly, this is just currently how it is currently in Roblox. My suggestion is just to try to hide it. Add some objects near the edge like shells or pieces of grass.
This video may also be of some use:
Are they ever going to fix it?
Well, I can’t say for sure. But looking at the pattern Roblox is following with their updates, they are constantly trying to improve the visuals of Roblox. It is likely they will eventually make the terrain blending between water and land smoother. But keep in mind, one of Roblox’s focuses is to make sure their games have good performance.