Matej, thank you very much for your insightful comment.
The short answer is "yes -- most of the times". Your question was one of the first ones I had to answer to myself. Now, if you do a careless (not sharp, not well lit, not clean, not pleasant/interesting) photo of an uninteresting theme, it can be mistaken for a careless photo from an ignorant. You don't want that, usually.
My composition tutor at the IPF never told us a composition rule; instead, she made us look at dozens of photos, and tell why we liked or disliked them. Most of the time it had little to do with composition rules. So, I believe in this, too: "Now to consult the rules of composition before making a picture is a little like consulting the law of gravitation before going for a walk. Such rules and laws are deduced from the accomplished fact; they are the products of reflection..." -- Edward Weston. Of course composition rules are important, but of course you know you can make pictures technically and compositionally perfect that are painfully drab -- the "sharp images of fuzzy concepts" Ansel Adams talked about.
In the decadence photos (I prefer that to decay -- you aptly described the building, that looks like the nude of an old woman, who had her glorious days, as Rodin's "Celle qui fut la Belle Heaulmiere") there still has to be some harmony; not necessarily nice, certainly not unpleasant nor gross, but harmonic, it has to make sense, it has to be felt as a (neglected?) part of life.
And, of course, you must get your point across, even if it is just plain visual enjoyment.
Even when you completely throw away composition rules and make "unruly" photos (as in some Callahan, Friedlander, Frank) there still has to be harmony, or, if you want, some quality that makes them pleasant even when they're perceived as not being the regular stuff. You are, then, experimenting with composition, and there you went into doing brave new photos.
I don't think I might have done much new stuff, nor do I think I might have been too successful at it (and it's harder), but I think I don't want to limit myself to doing just the regular things when there's a world out there waiting to be found. Of course I still do the "pretty picture" stuff, but it became just a small part of the photographic game and fun. It would be the same as doing "it" only in the missionary position, or just what's prescribed in the Kamasutra.
I'm glad to find photographers on this site who are willing to shoot scenes that are not beautiful, colourful and happy. B&W photography is particularly strong in images like this one.
Of what I've seen of your portfolio, this is the photo that speaks to me the most. It is a convincing documentary of a place that used to pulse with life, yet now lies in abandonment and disrepair. I hope you post more pictures of this sort.
I would like to know your opinion on a question that came up when I was doing shots similar to this one. When photographing unpretty pictures of decay, how much effort should be placed on obeying the classical rules of photography? Should one try to keep the photo 'clean', to use a 'pleasant' composition, etc.?