This is a bit off-topic, but it's actually quite feasible to get a real edge in Hold'em, and it's not just about spotting other people's patterns.
To start with, there's simple probability: knowing the odds of making you hand vs. the payoff in the pot, or the chance of winning with various starting hands. This is pretty basic but a lot of low-stakes players screw it up. If you get it right, their mistakes are your gain.
At a more advanced level, game theory comes into play, using bluffs and so on. The game is complex enough that it's not completely solved, and it's an active area of research. The University of Alberta is doing a lot of working developing poker bots using game theory. By playing a good strategy, you can prevent other players from exploiting your patterns.
Only after you've got a good grasp on all that should you really think much about exploiting a particular player's weaknesses. The Alberta guys are doing work on that part too. Exploitative play can improve your profit but also makes you more vulnerable.
For a good overview of this stuff, the book Mathematics of Poker by Ankenman and Chen is a good place to start.
I agree though that HFT is awfully competitive these days. If I had to choose between the two I'd play poker.
I have done HFT, played heads up semi professionally, and for my bachelors thesis wrote a paper on a PLO playing bot. I studied Alberta's research and it is phenomenal. The parallels that emerge between HFT and a pokerbot is essentially that the architectures of both systems are kind of same and the details are kind of orthogonal. The edge in Hold'em is kind of gone. The 1/2 games right now are as tough as the 25/50 games 5 years ago. PLO is still pretty exploitable though. The same is true with HFT. Most strategies in HFT no longer work but there are definitely ones that still give you a lot of edge-you just have to think harder : )(just like three betting preflop and cbetting the flop doesnt work anymroe).
The same could be said of HFT. Traders are "skilled" at having nanosecond access to the orderbook, having their servers co-located in the same rack space as the exchange itself. They are also "skilled" at recognizing a price movement nanoseconds before it actually happens and getting their order in just in time.
But the HFT game changes and you have to keep up. Just as a poker player from 10 years ago would not survive in the game today without adapting his style of play.