It's not true. Optimization is usually very expensive. The more complex game the more complex optimization. It's not like you invest 10 % into optimization and gain 30 %. It could be 200 % into it and get 25 %. SW is so much complex and if the engine is old there is probably very much old code and who knows how many talented guys from ISI stayed. You need best talent, a lot of money and a lot of time to have great SW. Many companies don't have anything from it. I don't know situation at all but "being lazy" is rather standard for normal development because nothing else is possible. Current game looks rather good. And mostly, you can't sell optimizations almost to anybody. Try to ask investor about few millions you would like to invest into just optimizations.