It's not your only choice, it's just your only choice that's currently available.
Plenty of 1920x1200 options if you go back to Core 2, a few at Nehalem, and a couple at Sandy Bridge. (Some of those in the Core 2 and Nehalem days are even 15".)
Also, if you go back to Core 2, and don't mind some frankensteining, you can get an IDTech IAQX10, IAQX10N, or IAQX10S panel, a ThinkPad T60 or T60p, and a T61p 14.1" 4:3 motherboard, heatsink, Socket P CPU, and PCMCIA slot assembly, and put them all together. Need to reflash the panel's EDID ROM, and file some stuff away from the chassis, but the end result is up to the following:
2048x1536 IPS display
2.6 GHz Core 2 Duo Penryn
Quadro FX 570M (but crippled, and 128 MiB VRAM only)
8 GiB RAM
Whatever SSD you want, but IIRC it's constrained to SATA 2 speeds (maybe SATA 1, actually)
With less frankensteining, you can run the T60p board, and get up to the following:
2.33 GHz Core 2 Duo Merom
3 GiB RAM
Whatever SSD you want at SATA 1 speeds
And, with zero frankensteining, you can find an ultra-rare config of the ThinkPad R50p, which means up to (I think):
1.7 GHz Pentium M
Radeon 9200 or so IIRC
I think 2 GiB RAM?
Whatever PATA SSD you can find
The T61p/T60p frankenstein is what I ran before getting a MacBook Pro Retina, I'm a bit of a pixel whore.