If it helps to explain things further, let me try to describe how things work when the weather is fine and everything runs smoothly:
Understand that the National Airspace System, hereafter referred to as the NAS, was programmed and structured to cope with VORs and airways. Over the years, the Center's Host system was "taught" to understand Lat/Long coordinates, but Terminal Systems still don't. Then came SIDs and STARs, and our computers "understand" those. In other words, when you've been issued the CWK2.TNV for example, the NAS is programmed to understand exactly where and what altitudes you'll fly, so it knows exactly which sectors need the flight data, and what sectors will work the flight. The NAS knows whether to send the data to a Low, Intermediate, High, or Terminal sector based on published altitudes. The computers can initiate an automated HandOff to the correct sector without any action on the controller's part. All those SIDs (now DPS) and STARs are also codified in our LOAs with adjacent sectors, as are preferrential routings.
What all the above means, in simple terms, is that when everyone's flying published, preferrential routings, or even standard airways, or even direct to/from VORs, all the NAS computers "understand" exactly what the aircraft is doing, and works almost without a hitch distributing data from sector to sector. Controllers also aren't having to waste time with manual HOs and Point Outs, or other verbal coordination on landlines. Our LOAs cover 80-90% of typical IFR operations, right down to altitudes and speeds. I'm not guessing what fix the next arrival is comming from, or what altitude, I know. Likewise, the next sector doesn't have to worry about where my departures are going to cross his boundry. He knows exactly where as soon as he get's a strip. I may work a whole hour and not speak to the guy working the next sector.
When we start approving directs outside the LOAs, and outside the NAS's ability to understand, we have to go back to manually coordinating all this stuff. Something we don't mind when it's slow actually, but we can't keep up with when it's busy. The computers are forwarding data to the wrong sectors, which means the receiving controller not only doesn't have a strip, he may not even have a radar tag. You're just a [ * ] on his or my scope untill we manually force the data to the correct sector. We're constantly coordinating altitudes/headings to prevent conflicts at the sector boundries. Conflicts that don't occur when we're following SOP.
The more we controllers step outside the bounds of SOP, the more we have to do manually, and the less helpful the automation becomes. If that sounds trivial, imagine your FMS craps out and you're left with a Piper Altimatic and a KX-170. It's the same sort of situation.