That may be true, a lot of the big companies were slow to realize changes were underway... I worked for a shipping company that handled a number of computer companies...Telex, Tandem, Four Phase, Sperry Univac and such.... they were still the large mainframe types mostly. One of the companies I dealt with was called 2PI or TwoPi, not sure, but the company was started by IBM engineers that tried to sell their idea of the desk top to IBM and were turned away.... they sought financing from other sources, wound up with a consortium out of Australia that financed their start up and shipped most of their systems to Australia.... don't know if they're still around or were bought up by other companies or what happened to them... matter of fact, most of the companies I mentioned I don't hear about anymore.
My son worked for a company in Austin that did programing and something in computer security field... IBM came to the owner and wanted to buy them out. My son said that when IBM decided to take over a company, it was wise to sell or else IBM would just take the technology and bury the company with their sheer size... don't know how much truth, but his concept....the company did sell to IBM and he was absorbed into the IBM family for about 5 years until he got fed up with the internal politics and left for greener pastures. He did well there and it served him well, but he's glad to be more independent.
Another company I worked for in the late '70s was called Digital Telephone... they were a breakaway company from Lynch communications.... again, engineers with a new or innovative idea, approached their parent company who wasn't interested... so they started their own. They built the small behind the desk telephone switch boards... before the switching systems that are now housed in the warehouse or somewhere away from the reception area... and another unit that could be mounted on a telephone pole outside a subdivision and take the place of a brick and mortar substation. I was their first ever traffic manager, about 5 years into their operation... and the first year they actually showed a profit (not my doing).... technology was changing at a very fast pace back then... it was both fun to be part of it and a little daunting if you couldn't keep up with the changes....