Back when I started using electronic design automation tools Eagle was always my first and only choice. I grew to like the tool and learned a lot from it. Even after the software was taken over by Autodesk I still continued on with a license.
However, KiCad had always been something that I knew I would eventually get around to. Mainly because I was intrigued by those who swore by it once they started using it. In my opinion, something free will almost always get your attention when it is being compared to a paid product; especially if said product is holding its own. It also didn’t hurt that the tool was open source. So fast forward a couple years and here we are. I am now legit (Key-Cad) fanboy convert.
For what it is worth, I consider myself to be at ease with tools related to schematics, simulations, and 3D. But, learning another software and its quirks can be a turn off and daunting. Who has the time really? Which is why I would assume most stick with what they know unless forced to switch, e.g., job, paid project, etc. That being said, I am glad I decided to carve out some time to start giving KiCad a go. So far it has truly been a pleasure.
I have a couple of legit projects on the horizon that I am itching to start work on. KiCad will more than likely be my go to tool for that aspect of my projects. More than likely I will probably design a couple more boards with KiCad before I decide fully. But as of right now I cannot see any real reasons as to why I would ever go back to Eagle.