Quickly checked the Cryengine. Never used it before, and I like that some elements look almost the same with my vision. For me, this means that we’re heading in the right direction. And you know they did a remarkable job in terms of unified style, streamlined interface with the website and of course ladies and gentlemen may I proudly present to you the Flat. Line. Icons! (conspiracy! trend! 
Sorry, I couldn’t resist!
Regarding “looking so close to a competitor engine”, you know it’s like wheels or mirrors in cars, they all look almost the same, placed in the same places because of reason. In modern software, similar examples would be tabs, buttons, panels, etc. It’s called a UX pattern. When users understand all these things without steep learning curve they can not only do things faster but migrate from Unity3D or Cryengine or anything else easily. And this provides a huge benefit for the end user: speed, efficiency and less stress to migrate to another ecosystem.
And at the end the day this can be useful for engine creators too since they will serve less low-quality users.
Sure those switchers can migrate because of lack of certain features, but not “bad UI” excuse anymore.