Because this CfB software developer (who is BTW hiding in a the shithole of communist Belarus) has never worked for any notable software company, he has never worked on any commercial, never mind enterprise software project, and therefore he could never learn basic software engineering principles by being the member of a normal software development team. His only software engineering credential is NXT, JINN and IOTA which were good enough to scam the idiots, but as you can see don't even pass a basic QA check-list, never mind a code review. That's why you find disturbing issues in his code as well as in his design (probably Sergey has no clue what is the difference between design and coding in software development).
How much are you willing to bet on that? Should be easy money for one of us.
Fix you flawed design wanker and come back when you understand software engineering. Software engineering is more than writing 12 java files for these idiots.
As I said, you are hiding in the shithole of communist Belarus, because - apart from the scammer David boy who hired you remotely - no software company would hire you in the western world.