Let's ignore the DS angle for a bit, since I suspect many corporate boardrooms were opposed to Trump for more reasons than just being infiltrated (some may not be infiltrated by DS players at all). I want to bring this up because I feel that Trump and the Patriots exposed these people as well, and I'm probably only touching the tip of the iceberg.
Business Competition - Trump created an environment (by removing regulations) that allowed small / new businesses to grow and thrive without having to have the resources to deal with corrupt government agencies
Labor Market - job growth creates a tight labor market, which gives people options to move around and seek better jobs and opportunities for themselves
Labor Competition - requires companies to pay higher wages and/or better benefits
Control over employees - amazing how covid showed that many people can be productive working offsite, which made life easier for people who had to be onsite (parking, commuting, fuel costs, etc) - but now those same corporations feel their people must be onsite full time to get work done, when it clearly has nothing to do with getting work done.
Political Control - a few large corporations are easier to control from a political standpoint, than many smaller companies. The people running the large corporations benefit from having a symbiotic relationship with politicians, being better prepared (advance warning) for regulations and government manipulation of large markets. I suspect they feel they can strongly influence and exercise some control over the political side, and profit from it.
Corporate leaders and their companies were all subjected to discrimination, bias and repression by the Main Stream Media and Big Tech, in addition to corrupt government officials.
Anyone who supported President Trump could be silenced in the media, banned online, ridiculed, boycotted and basically cancelled. Due to all of the corruption involved, a corporate leader who supported President Trump, law and order, or simply supporting and donating to conservative politicians faced a lot of pressure. It could also cost them their careers, or cost their company significant money in lost sales and lost government contracts.
Based on the vast amount of corruption in the media, Big Tech and all through the government (and in education)... it's no wonder many corporate officials wouldn't publicly support President Trump. Many did privately, or at least they appreciated the things he did for our economy... but publicly, they didn't want to take that risk and subject themselves and their companies to abuse.
That's a great point. Thanks for adding that to the discussion.