Owners (shareholders) and boards are not full of idiots either. They realize the temptation of short term pumps. Thus, executive compensation is typically shaped to encourage longer-term thinking (e.g. stock that does not fully vest for years, bonuses based on future company performance years out, etc). And if they do reward short-term metrics, it's for a specific reason.

That said, japanese companies tend to have longer time horizons than american companies (decades vs years) and perhaps that's better. But then again, the further out you go, the less your planning will work out. So who knows for sure?

Yep. Arguably an over-fixation on "short term profits at all costs" would be a gross violation of one's fiduciary duty if it puts the long-term viability of the enterprise at risk.