Surely if you can read the relevant area of the brain, and have the computing power and understanding of neuroscience required, then any thought is readable.

There no way you read billions of neurons accurately at the same time. That just not feasible. The thing you can do is reading a bunch of neurons or reading a signal that aggregates the activity of a bunch of neurons.

Why should this require any extra effort on the part of the brain?

Nearly all BCI designs that are used in the real world take effort. A bunch of them even have a learning curve.

Are you a neuroscientist?

Depending how on wide you define the term. I have set in university course on neuroscience that discussed BCI's.