“has text” is talking about the type of data on the clipboard.
So if you set the clipboard to an empty string, the “has text” will be true - there is some text on the clipboard, which happens to be the empty string.
If you set the clipboard to an image, then “has text” will be false.
Command-C with nothing selected will not change the clipboard, but I presume you know that, you’re trying to detect it.
Personally, I would do something like this:
Set Clipboard to "KMEMPTY"
Command-C
If Clipboard is not “KMEMPTY”
If you are trying to determine whether or not the user has made a selection, and whether or not the clipboard has changed, you might consider this approach: