could go on and on and on. My preference for keeping the same proportion is most probably the architect in me, or maybe thePurist in me
However, with time, we people who use proportions in our everyday jobs (not only architects, but maybe also graphic artists and other designers), find it interesting to limit ourselves and try to get the most out of those limits. I know it may also sound as a straightjacket of sorts, but I think that, whenever possible, one should try to compose from the moment one aims. I'm not against different cropping options, and I think that my insistence is probably my very personal compulsive disorder, or plainly that I just don't know how to do it. I've had two exhibitions (no big deal), and I find that it looks very nice when all the photos show some consistency. But, again, this is a very personal opinion.
Your photo has proven interesting in awakening this debate precisely because it has many interesting things going on. Would it have been "simpler", it, of course, would have been an easier cropping decision. I also think that this is why black and white works better with street photography: taking color out of the picture (literally) distracts less and keeps already a very inclusive picture simpler.
Don't know for sure... but I like to question things. And, of course, only my opinion.
