I understand that the board felt they could grow the marketshare with clones but history shows that you just end up cannibalizing your own market space.
History has many examples of people who tried and those who avoided cannibalising their own market share. Sometimes it works, sometimes it doesn't. It's more to do with the execution & Apple did it wrong.
Whether it's the lack of Steve's reality distortion field, or other changes in the computer world, Apple are losing market share in PC's now and when the loss hits critical mass then it's game over.
http://uk.businessinsider.com/apple-mac-lost-most-pc-market-share-in-2016-chart-2017-1?r=UK&IR=T