That’s like, your opinion, and we all know the common analogy to that :D
Java is a tiny language with not too many concepts going around sitting on top one of the best runtimes with one of the biggest ecosystems. It is a very sane and good choice for almost every program out there, especially that empirically we have absolutely zero evidence for any significant difference between language productivities, other than managed languages being a boost (so your mention of C, which is arguably a language with so many faults one could fill a whole book about, is frankly, quite laughable).
I'd just like to take a moment to reiterate that object-oriented programming is a mistake produced by cargo-culting half a dozen different styles used by competent programmers (including the devolpers of smalltalk and its relatives, from which OOP appropiated its name), and that Java is completely unusable by anyone with a sense of self-respect and a awareness that programming languages can be better than least-common-denominator noe-COBOLs. I'm not familiar with the specific codebase you're refering, but it would probably be at least less massive and less awful if it had been written in a more decent language, like Haskell or C.