Does your county have emissions testing? If so that could be part of it... most shops will not take on a project that will make them responsible if it won't pass smog afterwards.
Even if that's not an issue I can understand not wanting to deal with it. Once you take on something like that...you own it...and you will own every issue the customer ever has with it. Plus there are so many variables with Ford EFI swaps, and very few people know them really well, and add to that the fact that nobody builds new standalone harnesses for them... even a really good shop could have many hours into just sourcing parts from junkyards and then sorting out how to make it all work.