So now I'm doing some research, and finding issues:
The Y50-70 is a Haswell. The Macbook Pro is a Broadwell. So you're complaining a last gen PC with a current gen Mac. Maybe not a huge performance difference, but if you at least want to be fair, go find a fire sale previous gen Mac to compare with the fire sale pervious gen PC, or compare with the Y50-80 which is actually Broadwell.
When I jump to the Y50-80 (with SSD) the normal US price is $1,799. They're running a sale at $1,499. The sale price is somewhat competitive with the 15" Macbook Pro. The non-sale price really isn't.
The SSD it uses is pretty cheap, not PCI-E, not that fast. So they're trimming price because the SSD is about 1/3 of the speed of what the Macbook Pro ships, possibly 1/4 of the performance, and cheap SSDs are cheap. The GPU is fast, but the 860m is very hot. The CPU is a little beefier. The screen is higher res. The battery life sucks balls compared to the Macbook Pro.
So yeah, it's cheaper. But it's not really comparable. You're definitely making tangible sacrifices. 5 hours of battery life vs. 10 hours is a big issue. An SSD 30% the speed is an issue (and you can't even configure it with a 1 TB SSD).
The Y50-80 is clearly designed to be a gaming machine. The Macbook Pro can play games, but it's designed to be a work machine. If you're into just gaming the Y50-80 looks like an ok choice. But as a work machine? Please. It blows giant chunks. The battery life and I/O are unacceptable for pros working in big applications. It's not a work machine. If you're looking for a bunch of slow components tied to a giant power sucking GPU, a Mac isn't going to be for you.