There's nothing wrong with light entertainment. But they told me it was so much more than that, and I believed it. I still believe it could be more and that belief is perhaps what really keeps me coming back to SL.
It all depends on what kind of "more" that you're after...
In this thread CCC expressed that it helped her with her dysphoria, which is nothing to sneeze at.
Myself, it vastly, vastly, vastly improves the quality of my life to be able to go someplace "sunny" and "tropical" during the winter -even if it's only an imaginary (someone in
this thread on quora makes the point that making a distinction between "real" and "imaginary" when it comes to virtual spaces is arbitary) place. In Alaska the winter is long and dark and it fucks with your head -I experience that as kind-of seeing everything as monochromatic by the time spring comes around (that's the best I can put it, when the sun comes back colors seem to pop back and become much, more vibrant than during the winter).
I use SecondLife and Opensim to unfuck my head -it's not World Peace, but it makes me feel better.
On an individual level SL (and "akins") lower the barrier of creativity and self-expression, both finacially and also in terms of "barrier to entry" ("the magic begins with one holy cube") -you can come in here knowing fuck-all, sling some prims around while you're not going to end up in the Louvre it can be artistically/personally gratifying
...particularly when coupled with the hypergrid and the ability to share your wank with others in foreign lands, and to take in their wank as well.
It's very empowering, and that's glossing over the empowerment angle brought by opensim.
Again, none of these are world-shaking and niche hobby will always be niche; but it can and for many people (raises hand) does have a tangible and signifigant benefit to their lives beyond simple "light entertainment"
The problem comes in when you put all the expectations on it that goes hand in hand with the term "enterprise" and think it's going to be the next e-commerce whatever. Yeah, all that was bullshit and we rightly laugh about it.
It's a matter of perspective; and the way I see it SL/OS can be light entertainment, and it can also be an important tool in one's RL utility belt (not the only one, of course, certainly not the primary one) to make our way through this increasingly shitty world...