A lot of that is because getting something launched was so hard (time, money, dealing with government grants, etc.) that they made damn sure the thing was going

A lot of that is because getting something launched was so hard (time, money, dealing with government grants, etc.) that they made damn sure the thing was going to be robust and work. The prices SpaceX will be launching at allows us to just chuck some off-the-shelf hardware together and not care so much if half of the hundreds of probes we send out fail.