AlanRobertson's battle cry is Complexity Is The Enemy of Reliability!
There are several reasons he believes this to be true:
Simple systems are far more likely to be correctly understood by the SysAdmins that manage them, than are complex systems. This is particularly true when working with too little sleep or too much pressure.
Both circumstances are common to SysAdmins. As a result, more errors are made in managing complex systems than in managing simple ones.
For these reasons, the Linux-HA project strives to keep their software as simple and understandable as possible.