If you think of it as being another physical location, then yes it's stupid. If you think of it as having a level of reality that can be mapped into a visual metaphor where in your metaphor you can hurl a ball of fire at a server and destory the server, then yes, it's stupid.
But viewing it as a set of constraints in a parallel universe makes sense.
E.g. On Planet Earth we have a distance function. Give me two locations, and I can tell you the great circle distance between them. A different distance function will give you one of several highway routes beween them.
In Cyber earth there is also a distance function. Generally called ''latency' Physically I live 50 miles from the University of Alberta. But the U of A is 750 ms from me. My local library, 10 km from here is only 35 ms from the U of A.
So Cyber Earth has a very different 'geography' Places that have much longer latency can be visualized as being on high mountain tops. Cyber Earth looks much like a spiny sea urchin with most of the space being very high 700 ms plateaus on a 40 ms diameter sphere.
There are entire transactions that can take place digitally e.g. you buy a digital song with digital representations of cash. Similarly the people I know as online personalities that I've neer meant. In that sense, cyber space is reality.
Also, that bits can move across borders mostly without impediment, creating confusion about jurisdiction when a crime has been committed, that lends some sense of reality to cyber space. (Dammit, it didn't happen here. I happened in Cyberspace)