I agree and Dudley is something of an extreme case- for many years now, every so often they announce massive development plans as a result of new grants/funding being in place- but these just never seem to happen, and Dudley Zoo is still pretty much as it was 40 years(or more) ago. Financially they always seem to have problems even just maintaining themselves, while the grounds are full of crumbling Tecton animal exhibits which have Preservation Orders on them so must remain, but are either unsafe, defunct or despite their overall unsuitability, have to be recyled as fresh animal exhibits.
Overall its hardly a recipe for a Zoo to be able to take major steps forward.