This is an important problem. It's fundamentally a problem with the way patents are granted, and the way they are used, and the way they are understood. let's address these in turn:
First, you shouldn't be able to patent round corners. That's silly.
Second, you should be able to patent things and then sue people for using your patent if you are not using your patent in any way shape or form. An unused idea should be free for the taking.
Third, there's a great deal of ignorance about what patents are, how to get them, and how to use them. Behind this veil of ignorance, bad things happen.
Unfortunately, this state of affairs means that companies like Apple can and indeed must violate the spirit of the law symmetrically with it's competitors, to protect themselves until the system is fixed.
There is no doubt it's a bad scene, but it's not entirely Apple's fault. If they exercise restraint with these patents, using them purely defensively and then with great perspicuity, then I don't see how they could do any different.
Let us all direct our feelings toward reforming the patent system perhaps by joining an organization like "Defend Innovation"[1], the EFF's group pushing for patent reform.
[1] https://defendinnovation.org/