Umm.. no. Running the ethernet directly into the Genie isn't officially supported by DirecTV, so installers are required to install a CCK.
As to the CCK, if at all possible, ask him to install a Wired CCK rather than the Wireless one. The wireless models have a lot of trouble maintaining a connection (They seem really susceptible to interference).
Once the Tech has left, you can remove the CCK and run an ethernet cable directly to the Genie if you'd like.
One other little note.. If he installs an HR44 rather than the HR34, then it's possible he'll connect it wirelessly with the built in Wireless CCK that the HR44 has.. if he does, and you rather run the Ethernet cable after he leaves, you'll need to go into network setup in the menu (of the Genie), and "Restore Defaults" before connecting the Ethernet..
This is because once its connected wirelessly with the built in CCK, it disables the ethernet port on the back of the receiver. This is ONLY on the HR44.
An easy way to tell if you've got the HR44 Genie or the HR34 Genie is just look at the remote.. If the remote is all white, you've got the HR34, if it's Black and White, then its an HR44.
And if this makes no sense, it's cuz I just woke up and need more coffee.. just post and ask me to clear up the icky parts.. LOL