According to that version:
A suicide and a Buddhist both aim to end suffering by ending consciousness. The suicide mistakenly thinks that it is sufficient to end the present life. The Buddhist knows (!) that it is also necessary to prevent future lives. Thus, their goal is the same. A Buddhist is merely a better informed suicide.
On this view, it seems to follow that, if more people were converted to Buddhism, then more people would practice celibacy and fewer people would be reborn. Thus, for two reasons, fewer people would be born. The end result would be a planet without any human beings living on it. A standard reply to this would be that greed, hate and delusion, which cause birth and death, are beginningless and endless. Therefore, even if some individuals cease to be reborn, the Wheel will continue to turn. Nevertheless, on this view, an ideal outcome would be the cessation of all human births.
I do not believe in rebirth and, in any case, want to see the opposite, a universe full of intelligent beings perpetually learning and creating. The Buddha, on realizing his enlightenment, did not starve himself to death or remain in solitary contemplation but, motivated by compassion, taught the Dharma for decades. Thus, there was more to his practice than just the ending of personal suffering.
Buddhism preserves a particular form of meditation which can also be found in traditions with widely variant world-views, theistic, soul pluralist etc. Therefore, it is the meditation, not the world-view, that counts.
