Every company wants to increase its market share, which requires a continuing stream of new and improved products. All companies engage in in-house product development. The smarter companies also look outside to augment their resources and give them a competitive edge over those who don't. Why companies resist dealing with outside inventors. Of a 1001 reasons, the first 999 are fear of lawsuits.
Companies have much more to fear from outside inventors than inventors have to fear from companies.
When a company deals with outside inventors, it exposes itself to frivolous lawsuits. These can be brought long after the event. Memories of what transpired have a way of changing over time. The company finds itself in a David and Goliath situation, where the biases favor the underdog David. If the case appears to have even superficial merit, there's always a attorney who will pursue it on spec.