Honestly, I typically hear the opposite: 'no one bothers with hot sim'. The exceptions is, yes, when you *really* need that extra IP. Otherwise, why risk the Black IC? The +2 is usually not decisive, but also handy when you seriously need it. It *is* a desperate measure, or the purview of slightly crazy risk-taking hackers. And, in SR4, those not particularly inclined toward cost-benefit analysis.
Still, I'd definitely use that rule as written: "if the gamemaster feels a character is using hot sim too much". Everything nifty is bad for you in SR. That's the whole point.
I dig that, Epicedion. The GM was reaching in and teaching a newbie (honestly, not a 'hacker') a lesson. It's a lesson about not getting your admin account hacked, though. It's not really a lesson about what agents can reasonably do.