I make some pretty tight connections and my bags always seem to make it (knock on wood).
Sometimes I wonder if my luggage is even on the same flight as me. We have to check in so early these days, it would not surprise me if they chucked my bag onto any next flight that will get it to my final destination before I do. Probably not... but maybe.
Additional funny bit about that: The flight I got bumped from was from Seattle to San Jose with a layover in San Francisco (don't ask). I was able to get onto another flight to SFO a couple hours later but was going to be on Stand-By for the SFO-to-SJC leg. So I just arranged to have some one pick me up at SFO rather than stand-by for that last (short) leg. They picked me up at SFO and we drove straight to SJC to get my bag. Only... my original flight had been severely delayed so I actually made it to SJC before my bag... which left SEA a good 2 hours before me. o_0
A family member of mine worked for an airline on the ground post 9/11 and, barring a major issue at the departing airport, there weren't very many problems. The worst circumstances were short layovers (which usually arrived on the next flight and sent to their address) or reroutes to the wrong destination (which this person took the fall for, obviously, as it was all in their control).
My point is just that 1% is a pretty reasonable margin of error. If I worked on a team with 1% or less of errors over a life of a project, I'd be ecstatic. But, reality prevails. Email/Gmail, websites, cell networks, car accidents with hours of waiting, etc. all happen. Usually, only a small number are affected (or for a small duration).
I mean, seriously, this is the whole point of their job, and yet websites keep going down. Sadly, they fail at their job.
The physical world is much more difficult than the digital world. If the best and brightest can't maintain 100% uptime on a website, don't expect 100% success with something infinitely more complicated.