It's a far lesser ask to expect them to get three ICE, though.

Sure, because you assume the corp also has all the credits required to rez ALL of them, after rezzing IT Deparment and spending an entire turn placing counters on it.

Besides, you do realize that Guard is a terrible ice, outside of making Inside Job useless, right? It is strength two, and even by using the power counters you got the previous turn on it, it will still amount to a maximum strength 6 (+4 for two out of three counters, provided you placed 3 on IT Dept.). Not much of a problem anyway, unless your main Killer is the Femme (which would be a terrible idea anyway). And even with Femme, in a normal Andy with Datasuckers, you can use them to lower its strenght and just pay 1 credit to pass.

Unless all the rest of the ice is somehow very strong, and the corp somehow has the credits to pay for it all... well, you might be able to pass even without the Femme, go figure. And I'm not talking of theory, since I actually manage to trash IT Department easily most of the time... and sometimes I just have to invest more, which is always worth, to avoid a game lock status and my slow slow loss.

How exactly a corp is supposed to get a scoring window when all she does is prepare for IT Department? If you want a runner broke so he won't pass, you also need to spend credits to have him spend some.

A good runner player wouldn't just sit doing nothing while the Corp gathers the credits, the cards and builds her remote server for IT Dept... and unless the corp wanna get some protection on the central servers to avoid losing even before she can get IT rezzed, this means she has to invest time and resources on those servers too.

Not like a good player would make the corp play her game, now, is it? A good runner would make the corp play his game.

Keep up the pressure, make them spend time and resources elsewhere and they will have a hard time setting IT Department.