Well there is an opportunity for a landscape photographer as the 35mm panoramic Holga has only been out for a year:
its the difference between a camera that has personality than some sort of clinical "masterpiece" ... not to say that every image made by a
lo-fi camera is good, but that is the same for all the crapola being made by hassys, high end nikons, and ebonys with a schnieider xl ...
but YMMV ov course ...
I think pros that shoot Holgas/Dianas do so because they're confident in their visual skills. They can't rely on technology with the cameras, and image making is reduced to its purest form- just seeing.
The photographer's eye and brain are the important parts - the camera is just a tool. The results are predictable once you've run a roll or two through a new one (I have two and they aren't the same). You just have to know what scene and what lighting will work. And for some reason, Holga shots frequently work well on lith (see gallery here for examples, there are many from others way better than I).
Of course there are pros using Holgas. If we know their names is up to their marketing. Whether a print sells to people other than other photographers is entirely due to the results, not the camera. A buyer doesn't usually say, "I will/won't buy that because they didn't use X camera."
At least one of mine is quite sharp in the middle (or can be), but it's nicely OOF at the edges (barn shot shows it well). And, yes, I have a Hasselblad and I use it for different results.
If you're going to drive off-road, you take the Durango, not the Mustang. When the need for speed kicks in, you want the Mustang. It's all about having the right tool for the job at the right time.
Go to the Gallery and look at jbridges' work with a Holga.
But two conditions should apply. The first being that the photographer able to make the fuzzy image exciting should be able to make any other camera produce an exciting image. The second that those who like to demonstrate sharpness should aspire to make an image that is sharp and exciting.
Too many photographers find a comfortable niche and fail to stretch themselves or court disapproval, but the Lomo movement has shown that photography can be exciting, now those photographers need to broaden their language. And with a lot of them being young and open to ideas, a lot are now broadening their photographic language and technique. And visa versa, some of those photographers intent on using convention above all else should broaden their outlook and ask themselves 'who am I trying to impress if my photographs send people to sleep?'