Even moreso: Microsoft actively retarded development in the field.

Before Microsoft, if it didn't work, you sent it back and demanded a refund. Crashing was plenty reason to demand and get a refund.

It was Microsoft that got people to blame themselves when things didn't work ("did you try rebooting?") and never, ever offering a refund. Microsoft got people used to "defragmenting" their disks. (Nobody has ever needed to defrag a Linux filesystem.)

Remember when it came out that Windows 95 would crash all by itself if left running for, what, 39 days? Nobody had ever got it to work for that long. Before Microsoft, a crash meant you had to reboot, and that meant a product failure. After, crashing didn't even have a name, and I was shocked to learn that "crashing" now meant you had to reinstall the OS, which everybody just did regularly, in case it might fix something.

So, no: Bill Gates provided strictly negative value for his $billions.