Proprietary everything is stupid.
Just a thought, but doesn't apple do the same and everyone thinks is the bee's knees?
I DO work for Sony, so I am probably a bad example, but even my brother, who is an avid Nikon fan, admitted that the A77 was a pretty slick camera. I think the reason a lot of people buy Canon or Nikon (as their first camera) is because they ask someone they know is a photographer (amateur or pro) what camera to buy, and the natural choice for that person is recommend the brand he uses. Ussually he uses that brand because (1) it is a good brand (seriously, all of the main brands producing DSLR are making good products), (2) they already ave an investment in lenses, which would require additional investment if they changed to a different lens mount, and (3) they are used to the controls. But in all honesty, saying that one BRAND is better than the other, at least to me, is like saying what color is prettier (which, by the way, everyone knows it's green!). You can argue that X model is better than Y model, but it's hard to make the point that brand A is better than brand B. You can probably argue that brand A is better for XY purpuse, but not in everything.
Having said all of the above, I can tell you Sony is competing rather well (at least in my market, Central America) with Nikon and Canon, and I also can tell you that I found it curious that in the report WHATS NEXT on Digital Photographer (or was it Shutterbug?), many of the new technologies they see as standard for the future are already in production with Sony, such as the EVF. I think EVF will eventually become the norm and OVF the exception as time goes by, we will see more and more cameras implementing this. Of course, I think the EVF will also improve drastically to overcome most of the things people complain about it... Another typical comment on Sony is that the glass is not as good as Nikon or Canon, but if you compare the G series or Zeiss glass, they more than hold their own (not to mention all the other third parties that make glass for Nikon or Canon that are lass now making glass for Sony as well, such as Sigma, Tamron, etc.). Oh, and yes, there is a reason why nikon is using Sony's chips in their camera; if Sony's sensors were all that bad, I doubt such a well known, prestigius brand as nikon would risk using it.
Now, to the OP, I do think that Sony's entry level cameras are pretty good. I compared my niece's Canon (dont remember the model, but it was also an entry level DSLR) to the A37, and the A37 stood its ground rather well. I think the problem is that a lot of people make their opinion BEFORE they have personally tested the product, and base their opinions on what others have to say about it.