Not timing per se but maybe not the stomach and/or resources for litigation.
For example, Jerome Lemelson, who was arguably the most successful American inventor (in terms of money received, not brilliance - some of his 600 patents are questionable) in decades, was a patent-holder of many key patents relating to magnetic recording. And stuff like the flexible track used by Mattel's Matchbox cars.
He spent years in court sueing the big players like Sony to pay him licensing fees. He ultimately prevailed in many cases and now his foundation helps support patent rights for inventors and helps bootstrap and reward promising inventors.
"You cannot develop a reputation for somebody who gives up. You have to be known as a fighter for your rights. Otherwise, you'll never license anything...Even Thomas Edison had a tough time supporting and protecting his patents. He spent about $1.4 million [to defend his inventions], and this was around the turn of the century, when beer was a nickel." -J. Lemelson