Eh, the chance that data I care about will get corrupted in a way that matters is very small. ECC also does not eliminate errors, just reduces them by some constant proportion. Something quite rare becoming say, 10 times less likely doesn't really effect my decisions much. If you're using ECC you can make the exact same argument that you need another bit of parity with the same justifications of making something rare, rarer. Of the things than can go wrong with my data, small corruptions from memory bit flips are far down on the risks to worry about.
If you're Google (you're not Google) then the scale of errors becomes a choice of optimization.
If you're Google (you're not Google) then the scale of errors becomes a choice of optimization.