Hey Massimo!
I cannot agree that this is "very different approach from the proprietary software". There is no one proprietary software approach. Neither is there any floss software approach.
Many proprietary developers are working closely with their users (Renoise is a good example) and many open source developers refuse to get any input from their users (will not give examples, enough controversy).
Another point is that for the end user it doesn't matter who reviews the code - proprietary developer or a non-proprietary one. I get huge amount of system updates to my Ubuntu. I have no idea what it all does. 4 months ago one of these updates broke my wifi and I had to re-install network manager, along with some of the drivers.
"I do not expect that a software that I use for recording music can do
nasty or evil things. But what about an email client, or a browser, or
an operative system?"
Really depends on your definition of "nasty" and "evil". Some people consider lack of anonymity doing payments as "evil". The are, of course, free to do that, but they should not expect others to agree with them.