Because the infringement has already happened. You don't just get to say "oops - I'll stop now" and get away free and clear. You still have to deal with the fact that you did infringe, and compensate for the damages that infringement did to the company and licencees involved.

So the choices are:

* Have a long and involved court case that you will almost certainly lose, where the press will continually poke you about the obvious and direct comparisons to the Samsung/Apple suits.

* Pay compensation/licencing fees, have the story become a non-story in a day or two, carry on using great piece of iconic design.

No brainer.