For example: "I don’t think there is anything particularly new here. PG says that the definitive description of good founders is “relentlessly resourceful.” I’m pretty sure that “toughness” is a big part of that. Can you take care of yourself and get (sh)it done, or are you a wimp?"
I'm pretty sure that "relentlessly resourceful" and "tough" are largely disjoint. Likewise, taking care of yourself & getting shit done, and folding in the face of adversity, are not as related. Why did he choose those things as either/or? It's a strange choice. So it's not wrong, really, but it's not really right, either.
Being "tough" can help founders be successful, but i don't think it's causal, just highly correlated with what are actually the good predictors. So the author banging his chest and talking about how he can just hear you describing his company as so damn tough is -- while not false -- not very useful.
or how about this: "Tough people choose decisiveness over diligence." That's just terrifying that he would present this as a choice, and i would run away from having him as an operator. First, it's a false dichotomy, but more problematic is that it doesn't matter how decisively tough you are -- if you're shooting from the hip, you'll miss. Is he trying to address analysis paralysis? Because if so, that's a very strange choice in language he's used.
Put another way: In the post above by jiu-jitsu practitioner where he is describing grit, i think he's absolutely right to say that grit is something incredibly useful in non-physical arenas. As a boxer, i've watched a lot of people get through some really brutal places. However, that 'grit' emerges from some very different internal motivations, such as a) raw ambition to be the best, b) a deep fear of the shame of failure, c) for the sheer hell of it, d) because a girl is watching, and even it looked like e) from a sublime appreciation of the present moment. (Zen boxer, totally weird) -- but they all were able to push through places where I watch a lot of people quit, stop working, stop pushing themselves, etc.
When Mr. Godin is talking about the importance of actually shipping software, and the difference between people who ship, and people who don't -- he's not framing that in terms of tough vs. wimp. Those words are pretty loaded with anthropological baggage.
Actually, i'm finding myself repeating what api is saying upthread, so i'll join in up there :) My real contribution is that if 'grit' is the observed behavior, i think 'toughness' is the wrong trait to look for that produces it.