Blame the EU https://news.microsoft.com/2009/12/16/microsoft-statement-on-european-commission-decision/
So, where exactly did the EU force companies to install crappy software?
Due to EU MS had no other choice but to allow Crowdstrike to run at kernel level. At 6:00 Dave Plummer says MS was working to move antivirus software out of kernel but was hit by EU regulators
Did you notice how that is not an answer to what I wrote?
I'll spell it out for you: Just because Microsoft is not allowed to prevent some other company from building a product, doesn't mean that other people are forced to use that product.
Also, the premise of your argument, if one can call it that, is that Microsoft would have been guaranteed to build a better product.
For all we know, Microsoft would have built that kernel driver ("the API") with a bug in it that would have caused millions of windows machines to crash while using Crowdstrike, and then you would be going on about how the EU allowed Microsoft to prevent Crowdstrike from building their own kernel driver that wouldn't crash machines.
The point of having a market economy is that the market participants decide which products thrive and which don't, rather than having the government decide, because the idea is that the broad market is much better at picking out the best products vs. the government picking the products that are allowed to exist.
Your "argument" here is that the EU government should decide which company is allowed to build the kernel component of security solutions, rather than have the market decide which vendor they prefer. That's what is called a planned economy, i.e., what the USSR tried. As you might be aware, that experiment failed catastrophically.
All the EU did here is that they guaranteed equal market access to all vendors, so that the market has a chance to decide. Your demand is that the EU should have picked Microsoft and should have allowed Microsoft to prevent competition.