I'm a former Windows developer (i.e. working on the Windows development team), having worked on the Windows networking stack, the Windows kernel and the Windows security teams. I tried Linux in the 90s and found it wanting. I'm doing a PhD currently and am only using it now because all the other pieces of my research require it (looking at Android etc.). I'm using Ubuntu 15.04 but still find Linux wanting. For example, I can't upgrade a Core i7 system to the 4.2+ release Linux kernel. It hard hangs on boot during (from I can see) an I/O APIC initialization problem.

In 6-8 months I expect to be done with my PhD and done with Linux too. Hard hanging on modern hardware with no error detection or fallback mechanisms and no useful output of debugging information is abysmal. One of the very first pieces I implemented in my own OS kernel written from scratch was kernel debug support from boot to desktop. This is not because I have to debug my code regularly (I can usually debug just by thinking through the code), but because sometimes odd things happen and you really need a way to look into the system and see what went wrong.

Every try "noapic" option on the boot? That option has existed ever since the miscompiled APIC code was generated by Microsoft software...

Sometime in the 1990s, I worked in inventory planning and production scheduling. The company I worked for used nightly batch processing of all daily inventory transactions, which meant that schedulers/planners were usually working with information that was 24-48 ours our of date.
The company decided to switch over to more real-time data processing, with each department on a lan communicating with the mainframe. Transactions from the warehouses (incoming/outgoing) was up to date and made planning/scheduling much easier from the standpoint of knowing what was available in the various warehouses.
The operating system which was installed was Windows for Workgroups.
I was curious to know what the OS was doing. It was a gui overlay on dos, so I decided to take a night school course on dos, followed by another on Windows.
It was while sitting around waiting for class to start, and browsing various computer related magazines, that I began to see mention of Linux operating systems.
One day, while shopping, I was browsing the magazine rack in the store, and picked up one of those mags which usually contains a cd of some kind (usually free/shareware games).
This one had a linux os cd - Caldera Systems OpenLinux 1.3.
I took it home installed it and began to experience the joys? of configuring lilo.
The more time I spent exploring Linux and how to do things via command line (which was no great problem since I'd taken the dos course), the more I learned, and the more I enjoyed having such intimate control of my computer os.
I'd occasionally boot window, and it would occasionally give me a BOD necessitating a reinstall to fix it.
Then on day after a crash, it refused to even recognize the cd (around year 1999-2001). I decided, this is it.
Booted OpenLinux, mounted the win partition, copied over the personal files I wanted to keep, then inserted the PartitionMagic cd, and wiped windows from my computer. Expanded my linux partition to take up the free space, and haven't looked back.
The last three computers I've had have not had the taint of windows os on them.
And I'm loving it.

Back in 1999 I got my first job at a computer helpdesk. A few of the guys there used linux, and I got install CD's from them. I played with it a little, and got the Red Hat Linux Bible (book that came with the OS on CD. Version 6 or 7...)

I didn't really use it as my main OS at the time because I had a lot of Windows programs already. I did setup a Linux box as a software router and used it to share a dial-up connection on my home network.

From then, I always had Linux running either on a separate box or in a dual-boot. I switched from Red Hat to Mandrake when GNOME 2 came out (Yuck...) and from Mandrake to SUSE when Mandrake died (I know it's still kinda around...)

For a while I was tri-booting Windows 98, XP, and SUSE 8.

Just last year I switched to Linux (SUSE Leap) as my main OS.