I think the biggest problem with the lack of BC is the way people have viewed Sony in the past. Whereas Nintendo went from one medium to another every generation, Sony decided to do a rather unconventional thing by allowing BC. This helped titles sell from the previous generation well into the next one. They argued that this allows gamers to save space and make that back catalog worth keeping. Cue 2005, Sony comes and says they are offering near 100% BC on their PS2 titles with the PS3, and were very quick to slam Microsoft for their less than complete BC on the 360. In fact, I recall that being a very commonly used attack on the 360 by Sony all the way into late last year, maybe even this year. And then comes the 40GB, and Sony is suddenly doing a 180 on their stance on BC. Not only is this hypocritical (especially considering how often it was used to attack the competition), but it goes against the perception of the Playstation brand Sony has built up.
Imagine for a second, that you're in the market for a Honda Civic. You notice that one 2007 version is $2000 cheaper than the other. You go "Sweet, I'll take that." You drive around some and you start to notice something strange; the mileage sucks. You're getting 15 Miles Per Gallon (for non-US, that's about 6.5km/Liter), which is far below what the other model is getting. You feel betrayed. One of the expectations of getting a Civic is that it is a relatively fuel efficient vehicle. Similarly, BC is an expectation for a Playstation product at this point. To remove it betrays that expectation, and to remove it mid-gen from one SKU will piss off a decent number of the 40GB buyers.







