How can we explain why investors in the euro zone are buying bonds at zero or very low interest rates when the ECB has announced that it wants to push inflation up to 2%?

Investors in the euro zone are currently buying bonds at zero or very low interest rates. Yet, the ECB is still announcing that it is determined to push inflation up to 2%. How can we explain this contradiction? Either investors beli eve that the ECB will be unable to restore inflation; Or investors are buying core bonds believing that they will make a currency gain if the euro breaks up; but this assumption is contradicted by the very low interest rates on peripher al bonds ; Or investors have such aversion to equity risk that they prefer to buy bonds with a zero yield .