We think the sign is the problem, it's 'language' and 'dictionary' lacks sufficient signs to do in-depth subjects and detail. Ask ANY deaf sign user to explain. You might just as well ask them to explain thermonuclear dynamics in depth. Mostly deaf were conned about how effective their language is. Rather than understand their education and sign was poor, they blame hearing for not signing explanations no signs exist for.
ATR has already reported deaf 'scientists' having no BSL signs to do their researches and work, and geneticists having next to no signs at all, surely the 'blame' lies with the lack of appropriate signs deaf can use and understand, and the failing (Perhaps questionability), of whether the language is anywhere near sufficient for deaf people?
Even Paddy Ladd was unable to do a signed version of his outpouring on the 'Deaf way' and the USA had to create a load of 'courses' to decipher his works, and without a 'Rosetta Stone' to help.