Chris,
In real life, as you may know, the computer spits out a route, and that's what you get, unless you want to get into some interesting negotiations. We don't have the same restrictions. We could actually clear you by anything we make up on the spot, in theory. As Alex said, though, if a TEC route exists, or an inter-facility LOA exists for your city pair, we will attempt to give you that.
There are exceptions, however. If a pilot verbally requests a different route, or if the pilot is unwilling or unable to accept the route we'd normally give (for a number of reasons), we'll try to get them in the air as soon with as little fuss as possible.
This is one of those cases where a 'realism slider' would be very handy in the software. Right now we have to somewhat use a crystal ball to determine the level at which someone wants to utilize the network.
Adam, to your point...it sounds like you want the slider set to 'fully real'. Consider it done

Kidding aside, the 'just file SOMETHING' technique does work in the real world, because, as you said, you're going to get what you're going to get. I don't subscribe to that method myself, but I know it's commonplace for many pilots.
Doing it here, though, I'm not sure you're getting the result you intended. We see a route void of SIDs or STARs between terminal areas, or not utilizing the published TEC routes, and we have to decide between:
1) asking if the pilot can accept the xxxx SID and the yyyy STAR, OR
2) issuing the xxxx SID and the yyyy STAR and seeing if the pilot accepts it via the readback, OR
3) issuing the xxx SID and the yyyy STAR, hearing the pilot read it back, and then watching them do something completely different in the air because they "didn't have any charts and would just prefer vectors."
Just about every controller here has done that dance...._thousands_ of times. When we're busy...here's what we do instead. We ask the controller above, "can you accept vectors HEC vectors LAX for this one?" The truth is...we can. For a limited number of pilots, we can. We can't do it for EVERYONE simultaneously, though. At any given time, we generally only like to have a small number of pilots in that boat, and everyone else on the controller equivalent of autopilot...on pilot nav routing around which our flows, sectors and SOPs are formed.
simroutes.com is a great resource for routes that have been vetted for flight in an online environment. This can remove a lot of the mystery, and if memory serves, it does contain the TEC routes, too.
In short, if you take the 'file anything' approach, we are not equipped to know exactly what it is you'd like to have happen. A number of people are really only just getting started with online flight here, and we try not to overwhelm them with the full court press. As we grow, our controllers are not going to be in a position to remember which pilots are new and which one's aren't, so we're in a bit of a tough spot on that one (without the explicit 'realism slider' in the software).
Apologies for the wrong email, but I thought I'd try to give an honest, detailed answer as to what we do on the routing side as controllers. It's a subjective art, not always a science.