the difference is that, ironically, the more build points there are, the less likely it is that the important parts of a base will be properly protected
this problem is not actually unique to high bp servers, it's just more apparent. people tend to spend their build points really poorly, but on high bp servers, they spread the base way out. the result is that the "base" defenses are farther away from what actually matters than in lower build point servers -- what people don't realize is that it doesn't matter how many turrets you have when they are all too far away or too cluttered to hit anything