If you want to actually act on move then dont use ascriptjob. Then use a node. But if you must act on sleection then use a scriptjob.
As a general rule of thumb this is a bit problematic question because it builds on assumption that its desirable for you to run your own code to do things. Well thats not how maya works. Maya is a automatic optimizer of a runtime environment. So maya actually runs code when it needs to. Whereas you are proposing of handling the thing yourself. And i can assure your going to end up doing a MUCH worse job than maya does. So yes by all means do this but you didnt actually learn anything valuable in the process.
In fact id go as far as to say that if your using a script job your almost certainly thinking wrong 90% of the cases. And if you think yoru code is the thing to do the processing in then your either doing the wrong thing, or putting it in teh worng place (as in you mean to use expressions) or mixing gui layer with computation.
See the hallmark of doing the right KIND of maya scripting is that your actually making nodes, and letting the nodes do the heavy lifting (its a bit like hiring/buying forklift for moving around boxes in a warehouse instead of building your own forklift for the job).
If on the other hand you think your code is important to be acted uppon in line by line computation manner your looking at the wrong module. You should be working with the api. But then again its not every cost effective to go and build the forklift yourself every time. So you should understand atleast the basics of the script layer before you do. Because you must understand nodes to work the api.*
- the bigger question is offcourse why use maya at all if you must dump whats good about maya away?
PS on a related note on the page of the link:
It's straightforward enough, but a lot of people make the mistake of opting for an
expression (you have problems triggering the expression.)
err.. no you dont, theres no problem triggering a expression. You just dont put MEL in expressions but you actually connect the enum to the attribute that does the driving... Just the kind of advice you DO NOT WANT TO HEAR.
I mean, not understating maya i get. but taking a solution that does work, and say it doesn't because you misunderstood everything fine. But take one problem and convert it into 2 deeper problems is just dense