Basically everyone wants to mimic Apple superficially. Apparently Lenovo thinks people are buying W540s because they look like MacBooks[1]. It wasn't enough to ship the X1 all weirded out, they had to go fuck up the rest of the line, too.
Lenovo even had a blogpost where they claimed "most users adapt" in a short amount of time. Not that there was any benefit, just that they needed to modernize the design and it wasn't that harmful. Idiots.
The X201t is like the pinnacle of their design. 16:10 screen (important if you use Windows, especially inside a RDP app - 1366x786 just doesn't have enough vertical pixels).
The X201 also had a FULL keyboard. They used every cm of the laptop to fit all the keys in. The newer X series 12", they remove keys, and added blank space around the keyboard. Here they are trynna cram stuff in, and they literally throw away 2-3 keys worth of space.
Lenovo is just beyond incompetent in designing things at this point. I don't know about the sales side, but since everyone else in this space is just as bad, it probably doesn't harm them. But if Dell ever wakes up and says "oh, hey, maybe we should make real laptops", they'd steal away ThinkPad's marketshare pretty quickly.
Oh and just to insult us on top of all these bad changes, they ship utterly crap panels with some of the laptops. I bought a T440p last year, and I absolutely hate it. It has a viewing angle of 0 - there's no point at which you can view it and get anything remotely decent.
1: I've tried MacBooks... the ergonomics are terrible, as is the heat. Beautiful displays though.