I do agree with the theory of a long term bear market in Bitcoin. I see this because of the following:
1) There is a widening chasm between the promise of Bitcoin,  a digital and fungible currency that can be used by anyone in the world to pay anyone in the world without the need of an intermediary and the reality a digital non fungible currency that can in practice only be used as a settlement layer between the intermediaries Bitcoin was supposed to replace under the promise.
2) The macro economic factors identified by Dent and Armstrong, namely a 30s type deflationary depression. What Dent got wrong is he failed to take into account the impact of the massive quantitative easing or money printing by the central banks since 2008. This would make a strong fiat currency such as USD attractive.

In the scenario above one would expect an overall bear market in crypto currency; however just as was the case during the 1930s with stocks there will be exceptions that buck the overall trend. Identifying the latter is where the real long term opportunities lie. Monero could very easily buck the trend since objectively it is very well placed to become the promise of Bitcoin. What this would point to for Monero is very strong long term prospects combined with extremely high short to medium term volatility and risk. My personal position is almost exclusively a combination of CAD and XMR with no debt. A convertible fiat other than USD can make sense where a person's expenses are denominated in that currency.