In my opinion any long term analysis of gold, which is priced in US dollars, needs to take into account the real loss of purchasing power of the US dollar and not dismiss the historical loss of purhasing power of the US dollar.
A simple long term chart of gold priced in US dollars, with those US dollars remaining a constant, does not do that.
That's also why all these "gold is in a bubble" arguments just do not make much sense to me. If anything is in a "bubble" it's the US dollar which has been created at historically unprecedented levels.
If gold was in a "bubble" then gold miners should be enjoying super profitable "bubble" profits. Most gold miners are still battling to make even half decent profits after ALL business expenses are taken into account, because the gold price remains very low in real, inflation adjusted terms.
In 1980 real US dollar terms, gold is currently only around US$200. (shadowstats.com reports true US inflation, not the officially spun US inflation figures.)