Because the silly patents in question are so broad (at least on paper, before trial) that they are practically impossible to not trip over.
Consider the "data detectors" (one of the patents Samsung lost on, IIRC). It dates from the mid 90s and had nothing to do with smartphones until some lawyer at Apple realized that it could be twisted to cover common features like recognizing phone numbers in text messages so you can click and call them. This one happens to be particularly egregious because it is the smartphone equivalent recognizing email addresses and URLs email messages, which goes all the way back to Netscape Navigator 2! (which is at least a contemporary of the patent, if it didn't preced it)
Unfortunately, we all know how prior art and obviousness arguments usually go...
Consider the "data detectors" (one of the patents Samsung lost on, IIRC). It dates from the mid 90s and had nothing to do with smartphones until some lawyer at Apple realized that it could be twisted to cover common features like recognizing phone numbers in text messages so you can click and call them. This one happens to be particularly egregious because it is the smartphone equivalent recognizing email addresses and URLs email messages, which goes all the way back to Netscape Navigator 2! (which is at least a contemporary of the patent, if it didn't preced it)
Unfortunately, we all know how prior art and obviousness arguments usually go...