There is a reason why people camp at level 6...

You might have gotten lv 10 if you did, since it would save you some runes on the 7 to 8 which can be then used for the final upgrade.

And also, Murphy's Law.

It hardly matters if 1200 would have worked 9 times out of 10 (not sure if it would, but let's say it does). No one bothers to publish unremarkable successes.

Because the 10% will happen. And when it does, people will complain.

So when human error and hand of fate meet, here we are.