I think the whole point is that BMW wants to distance itself from being considered a "traditional" brand. You can carry the same heritage design cues for only so long before all you're doing is refining the same car for the longest-assed time.

Look at Porsche. Put a 1993 911 next to a 1973 911, and they look like the same basic car. Same roof and windsheild structure, similar suspension designs, obvious similarities in the shape. Same fenders even. The 993 took the shape and modernized it a little bit, and the 996 is a completely modernized variation on the same theme. Granted the overall shape follows family cues and the change wasn't that drastic, but if you put a 996 next to any sort of air-cooled 911 you see no similarities beyond the thematic.

BMW is doing the same sort of thing, albeit a bit more drastically. The heritage design cues are still there in the grille and C-pillars, but the designs are being updated. Yeah they're being a bit wacky and in some cases the execution is not as ideal as the concept, but the whole point is to update the image of the car. At a certain point heritage just becomes old. I think the 7-series and Z4 are a bit wild, but the 5-series is definitely moving in the right direction (aside from the somewhat wacky headlights and huge minivan dash). It would have perhaps been better if BMW refined the new style during the development process and come out with a more unified sense of the new corporate look, but people look at the cars and still say, "that's a BMW." Sure some people overly attatched to how BMWs "have always looked" might be turned off by such nonsense as Flame Surfacing, but overall the brand is trying to separate itself in a marketplace where BMW-ness has been copied over and over again by so many different companies.

Am I a Bangle convert? No. The Z4 is plain-out weird, and the interiors of both the 5- and 7-series look retarded with their convex dashes and huge hoods over their iDrive screens. The exterior designs of the new sedans I have less of a problem with, they look modern and a bit wild whilst still retaining their Bimmerness.

I used the word 'whilst' in a sentence. Tight.