As you so aptly put it, "The only power shrines have is that of
defending themselves and those of us who have put forth our own
sweat and blood to construct and maintain these artifacts most
Holy to us"

Maybe your just misinformed, or possibly it slipped your mind,
but I'd like to point out that they have another really cool
power that lets you summon *everyone* on holy ground, usually
for the purpose of killing people, known as the "Rite of
Convocation"

Thakren, Everyone's favourite Convocator

Penned by my hand on the 14th of Scarlatan, in the year 231 AF.