As Dean mentioned, it is the intermuscular fat and the actual muscle construction in the brisket point that gives the desired texture of burnt ends.
I dug through some pics of my latest documented brisket project to see if any pics would help show what we're talking about...
The point is a tubular muscle, similar to groups of straws filled with the meat in varying sizes, with intermingled fat between the tubes. Here's a pic of a smoked point (pre-smoke separation from the flat) as I'm slicing it up to cube, re-season and smoke again. Look for the muscle grain and interior fat:
The flat is a typical muscle construction with smaller, more tightly grouped fibers in comparison to the point. This is a small section (~1lb) of smoked flat, but you can see the finer, more tightly grouped muscle grain and reduced interior fat:
This is a spiced brine cured flat (similar to pastrami) which retains much of the fat during smoking, and you can see very little interior fat in the muscle:
There have been a few asking about doing BE's from the flat, a beef chuck, or even with pork CRS's, etc. I would think that it would be difficult at best to get good results with anything but the point. When my BE's come out perfect, they have a slightly crunchy crust and sort of like a snappy popping chew on the inside. That's the finished texture I strive for with my BE's, and I can't see the same being possible with a different type of muscle construction. I won't say it can't be done, I just can't imagine any special treatment which would give the same results with another piece of meat.
I've never really spent much time looking for center cut (trimmed flat), or points. I'm quite content with a full packer and all the various projects I can use it for. The packer is just to versatile for me to want a flat or point only. Once you learn how to separate them (which is actually pretty easy) there are several ways to finish them up for some truely great eating experiences.