[HarryHirsch]

Low yields make the process-oriented sad, but what matters is absolute ability to produce; not yield

That would be true if reagents, labour and plant equipment were free, but unfortunately they are not. Consequently you have these strange creatures called process chemists who shave steps of the discovery synthesis, increase the yield, and get around difficult reactions. It's really quite magical.

When it comes to bulk chemicals like vinyl acetate (produced at scales of kiloton per day) another consideration is waste. It cuts into profit twice: you lose product and you pay for disposal.