Why is espgs only for cups-intern printers?

[Georg Funk]

Hi!
I've got a Lexmark Z51 Printer and had problems setting it up(I got it workin 
now), because I didn't find the lx5000-Ghostscript driver. As i posted on 
linuxprinting.org that I can't find the driver in any gs-version Till 
Kamppeter said to me that I should use his espgs; but the espgs from the 
ports collection doesn't contain any driver except the one for the cups 
standard printers. Till coded espgs to supoport  all drivers listed on 
linuxprinting.org, so why are they taken out?
Sincerely, Georg Funk