True, but the more stuff you have, the more likely things are to break. The Shuttle was built to be all things to all people. It's the F-111 of spacecraft, and that's no compliment in my book. To accomplish all those different missions, it had to have a lot of systems. Each system has at least one backup. A simplier vehicle wouldn't have needed so many systems in the first place let alone all those backups.

Contrast it with a far simplier vehicle like the Soyuz. They've been launching Soyuz spacecraft since 1967. The design has been improved incrementally and it experienced two fatal accidents early on. Today, the Soyuz booster is very reliable (over 98% - better than the Shuttle) and it's launch escape system has saved two crews. The basic SL-04 Soyuz booster is a derivative of the ICBM used to launch Sputnik and the later version used to launch Gargarin. They've flown over 2,000 SL-04 and SL-06 (has an additional upper stage for Molynia missions) with the highest success rate of any expendable booster. It's a fairly complicated beast but, because they've largely left good enough alone, is also one of the least expensive boosters available anywhere. The Soyuz capsules have been incrementally improved over the years as well while keeping the costs remarkably low.