well, the pure academic doesn't really care...
it's more or less just a very nice playground for mathematics... (that is with the assumption of an efficient market)
Academics have cared about the viability of trading, that's one of the reasons they study these things. Many of the Wall Street quants care about exactly these things and come from academia. The main conclusion seems to be trading is doable but hard- lol, tell me something I don't know.
I personally like to know all I can, articles like this will not make you a trader by themselves, however I do like to have a broader understanding of things when developing ideas. There is also one important issue here that people should understand: the autocorrelations used are simple pairwise correlations. My conclusion is that more complex correlations are not captured by such functions. In other words if you start looking at complex price patterns and bring in other variables other than price, that simply has not been studied.