Commercial software can be hard to learn, but free software can be hard to remember.
A few days ago I was working with a colleague reconfiguring a Linux server. We needed to change the network configuration, and because it runs as a virtual server, we needed to make changes to the underlying Xen virtualization configuration.
When we started we drew a complete blank. Although we had set the server up, we couldn't remember at all what to do. But examining at the server, we understood why. It had been running continuously for 688 days. It was a long time since we had needed to do any work on it, and we, with our middle-aged memories, had simply forgotten.
Contrast this with the chaos that is my PC. To prepare materials for clients, I reluctantly had Microsoft Office 2010 installed a few weeks ago. I have used the open source OpenOffice.org/Libre Office for some years, and earlier versions of Microsoft Office for ten years before that, but I had never more than dabbled with the new style Microsoft Office 2007/2010.
If you are used to a more "traditional" word processor, then Office 2007/2010 is a nightmare. Maybe some people find it more usable, but to my perhaps warped sense, it is a mystery. As a casual user, I spend ages searching for the correct options in the "improved" menus, and the rest of my time fighting the writing "aids".
I could give more examples. Some software just does its job quietly for years, so much so that you will forget how it works before you need to change it. Other software is constantly changing, and you are constantly fighting to remain up to date.
At the risk of generalisation, free and open source software tends to stability. Open source software comes into existence for a variety of reasons (personal and commercial) and is developed up to a point at which it "does the job". After that there may be some widening of functionality and deepening of options, but there is little to be gained by introducing major new ways of working that will just antagonise your user base.
Paid-for software is different. There is a danger that users will just continue to use old versions of software, and software revenue will dry up. To counter this, software vendors have to innovate. This can create valuable new features, but if there are no valuable new features to add, the marketing department will dream something up. Users are encouraged to "upgrade" to a "better" version, but may just be paying for change for change's sake.
I do not have any objection to commercial software, but neither do I see it as fundamentally better than free software. With commercial software, you may have to upgrade to new versions for the supplier's benefit as much as yours. It is expensive and disruptive, and forces you to relearn. In contrast, free software can be very stable.
So remember, if you install free software, make some good notes. Because you may have grown old before you need to touch it again.