They seem to focus more on the financial signals, as opposed the the underlying innovation, infrastructure, logistics, or even sales in some cases.
Overall, We've seen a pretty massive uptake, but we also only recently returned to pre-2008 valuations of companies. That's a decade of next to no growth in businesses (supposedly). However, I seriously doubt most businesses that survived the crash don't have more infrastructure today. Meaning, I'm confident they are actually worth more today (on average), regardless of what the financial signals say today.
That being said, I'm actually working on a project[1] which uses other signals (other than financial) to determine a companies worth. Primarily, we are focusing on identifying "experts" in a companies field, and determining the brand strength with those experts. We are also looking at financials, generally how often they are discussed, etc. but the real value comes from the experts opinion. Seems to work better than Paul Singer's approach.
Although, the one thing I will say about the potential for economic collapse is:
> Singer is among those fearing that very scenario. He is betting that an economic recession may be on the horizon and believes that, with interest rates already near ultralow levels, the Federal Reserve won’t be able to provide a sufficient quantitative-easing cushion, as it did during the 2008-’09 financial crisis.
He is correct about that :p, that's probably my largest fear in regards to the current fed policies.