Some examples of businesses INTC walked away from:

-The iPod
They had a brilliant MP3 player back in the day. Bigger storage and better interface that everything out there (until the iPod showed up). Died in less than a year.

-Intel Toys
They had killer stuff like a CCD microscope, which for $50 was better than a lot of lab grade equipment at the time. Killed in about a year.

-iPad
They had a tablet PC, ready to go...and shelved it. The iPad came out 2 years later.

-Cord cutting
This one's my favorite. They had the notion that people wanted a la carte TV and would be willing to pay for someone to...allow them to pick all the channels they wanted and only pay for what they wanted. You could also - wait for it - automatically record all your content and watch it on demand. This was back in 2011. They hired a guy from the BBC to run it:
siliconvalleywatcher.com - Interview with former bbc exec now head of intel digital home group

In two years they would sell this group to Verizon. Now, of course, outfits like Google make a lot of money curating ads for YouTubeTV and cord-cutting continues to accelerate.

In all cases they were saddled with the hubris that just because something had worked in the past...it didn't mean it would keep you on top.