I’d not heard about this before. Admittedly I only knew him from his cute anecdotes about early Windows development. Did a cursory search and I found this thread on Reddit: https://old.reddit.com/r/linux/comments/rb2xzk/dave_plummer_aka_daves_garage_former_microsoft/
There’s a pretty interesting comment by a user called Kefim_Wod, I’ll quote it here so you don’t have to visit that shitty site unless you want to.
TL;DR I don’t trust what that guy says anyway.
I really enjoyed his youtube channel until I found out about the business practices of his earlier company SoftwareOnline.com, Inc.
His company was sued by the Washington State Attorney General’s office in 2006.
atg.wa.gov/…/attorney-general-s-office-sues-settl…
Here is an excerpt:
The defendants agreed to pay $400,000 in civil penalties, with $250,000 suspended on condition of compliance with all terms in the settlement. They must also refund consumers who have filed complaints and pay $40,000 in attorneys’ costs and fees. The settlement terms prohibit the defendants from engaging in the following practices:
- Inducing computer users to install software by misrepresenting that the user’s computer is at risk for crashes or privacy and security invasions.
- Marketing its InternetShield software by means of a “free scan.”
- Using “buttons” in its advertisements that do not function as the user would expect them. For example, the X found in the corner of a window is normally associated with closing the window and should not open another ad.
- Installing software on a user’s computer that causes multiple pop-up advertisements when the user tries to close out of advertisements.
- Failing to provide a functional uninstall option for removing all software files.
- Failing to obtain a consumer’s explicit consent to purchase a product or a service.
Direct links to associated court documents: SoftwareOnline.com Complaint
SoftwareOnline.com Stipulated Judgment & Order
You can also find them at the bottom of the webpage I linked earlier.
Here is an article from 2009 that mentions it.
He greatly downplayed these events in his book but I’m taking his word with a grain of salt.
I freely admit that I developed a bias towards him after realizing he is a multimillionaire. Learning about that in combination with the information I detailed above really soured my perception of David.
I have the belief that more often than not very wealthy people are wealthy because they have taken advantage of other people to obtain that wealth.
I wanted to give David the benefit of the doubt because I really enjoyed watching his youtube channel but one google rabbit hole later and I felt like my belief was reaffirmed.
Also, the post includes this image, which… I mean it’s certainly a take. 
He seems like a M$ grifter. Big shocker.