In reply to margiematteson.

Just wondering why this was worthy of space and time ...

It's an exciting capability, to be able to know about the theme in use on a site, because theme enhancements or modifications to WordPress are of great interest, to people working to get WP to do new/different/cool thing. [Same goes for plugins.]

That the theme in use is not overtly exposed limits the understanding we can achieve, of the code behind a site. Since part of the 'deal' with WP is that it's Open Source, and thus available for examination, so we can all know what it is doing & how it does it, it's a little counter to the ideas & philosophy of the base-product, that the theme is obscure (it's an 'accident of history', that it works out like this).

WordPress is GPL, and derivatives of it are therefore also GPL. Themes offer the opportunity & means to modify the WP code-base (more or less), and to the extent that they create a derivative work (which varies...), they are subject to the same provisos.

There are proprietary themes, legitimately. Obviously, such products should not be creating derivative GPL works (tho some probably are). In the bigger picture, though, successful businesses catering to Open Source market-sectors (like WP), make their code GPL too. Their business-model does not rely on keeping their code secret. Indeed, they often 'make a show' of giving away the code.

Generally, themes are part of an Open Source product & environment, and it's at best going against the grain, to figure on keeping a component intended towork within that setting, closed & hidden.

So yeah, for sure - broadly speaking, WP-mods are stuff that we expect will be exposed.