"You have to write your design in an HDL language"

What???? There is a very mature set of tool for converting MATLAB to HDL.

http://www.mathworks.com/products/hdl-coder/

http://www.mathworks.com/products/hdl-verifier/

http://www.mathworks.com/products/filterhdl/

I'm sure there are similar tools for other languages. It requires you to program in a slightly different way (certain operations aren't optimal for FPGAs), but is extremely user-friendly.

At the company I work for, all FPGA programming is done in MATLAB. Unfortunately I work in a different department so I can't give you any technical details, but from what I understand, no one has written things directly to HDL in years.