If you have ever dealt with actual architects it should be obvious there isn't anything prestigious about architecture. Sure, a small handful of elites gets to plan really cool projects but the same is true for most industries -- everybody else just does boring grunt work.

The reason they call themselves software architects is that they're mostly working on software architecture. Granted, the title is overused because scantly few companies have the scale at which it makes sense having a dedicated person for that but I've seen plenty of "art directors" prettying up PowerPoint slides, too.

The problem isn't that there is no such thing as "software architecture", the problem is that it's usually not useful to extract it into a separate role (although that doesn't stop people from trying), making the title more ceremonial than descriptive.