It sums up his character arc really well.
In general, I feel like failure and mistakes are really interesting things. Most stories seem to ignore them completely, or fail to notice them in their own character writing.
Heck, one of the reasons I like FMA so much is that the main premise is basically "Hey, we fucked up, and now we're going to make amends as best we can"
This might be a little judgemental, but I also feel like a lot of audiences don't really 'get' mistakes in fiction. Like, a character has a lapse of judgement, or doesn't make the ideal decision, and suddenly the character is apparently garbage or trash because they aren't perfect.