That teaching obviously doesn't make any sense. This is one of the many teachings they will one day discard.
One of the major problem WT has is this 1914 nonsense. There are lots of doctrine pinned to that date. Until they remove that nonsense called 1914, they won't breath a fresh air.
Imagine, for over one thousand years now, God has not been able to get 144000 persons, but in relatively short time, the number of great crowd has numbered into the millions. Yet the standard of righteousness is still the same. Even the number that were available during the first century alone would probably get close to that 144000.
The 144000 likely refers to all true christians that would be saved during Armageddon. It is a symbol for all true christians during that time.
With time, the unreasonableness of that doctrine would gain greater vote among the GB members and they will change it. Don't be surprised that not all GB members or even those in HQ believe that teaching. JWs encourage hypocrisy, and love for organization more than love for bible truth. It's a sad reality.