Learning how to use Microsoft Office is 100X more convoluted and difficult.
SRP uses only a handful of simple, easy to understand concepts that children and grandmas use every single day.
No matter what software one uses, the person needs to learn it as there is a learning curve with them all.
What we don't appreciate (actually no publisher appreciates), is when a user installs a program and expects it to work for them without a single bit of effort on their part. Well, not even the most user-friendly software in the world meets that expectation. Look at something as simple as Shadow Defender with less than 10 settings, search the forums, and people have posted tons of questions about how to configure and use it.
There users out there who use defaults. Then there is the advanced user who is curious, willing to learn by putting forth the effort and maximize the protections provided by the soft. So all security softs generally offer users capabilities and protections across a spectrum.