GameNET looks at first glance to be very powerful.
"Hey look, it's a 'whenever'! It's always the 'whenever's that are the broken cards!"
Sadly, there's a bit more to this.
ICE is often bemoaned for either never firing or not doing enough, and that's for a good reason: the runner has the choice to let subroutines fire or to pay credits to break the ICE. These "punisher" effects that let your opponent choose what happens always play much less powerfully than they appear on paper — remember, when evaluating cards, you shouldn't look solely at the best case scenario: you need to consider the average case and the worst case too.
GameNET falls down because when the ID fires is almost entirely dependent on the runner. They choose when to run, they choose when to let subs fire, they choose when they spend credits on traces. Would you want your economy tied to the actions of your opponent?
Let's also look at it from a different angle: economy is most effective early in the game when you want to be setting up: you need money to install ICE, to rez ICE, to advance agendas, to play Hard-Hitting News. When does GameNET come into play? When your Gold Farmers and Turnpikes are already rezzed. GameNET starts raking in the money when you can force the runner to run through your servers over and over... but how did you get to that point? How did you get the money to rez the ice and to score enough agendas to force the runner's hand?
The answer is that you were Azmari EdTech instead.
Maybe GameNET would be less underwhelming if it had been released a few years down the road. As it is, the shadow of the slightly-too-pushed Azmari will loom over GameNET for most of its Standard-legal lifespan.