Which part? The strong AI part is full of bullshit assumptions, it's hard to know where to start.

Basic definition: a strong AI is an AI that can perform whatever cognitive task that a human could.

Context: diversity of preferences. It's not entirely clear what your hypothesis is, but it seems to be something along the lines of: strong AI is not possible because humans have such diverse sets of preferences.

Bad assumption: that there is no room for diversity among strong AIs. (Plural.)

It seems obvious to me that there will not just be one strong AI, but a multitude, each with different capabilities, personalities, etc.

What strong AIs will have that we don't is truly selective memory. It may be hard to imagine being able to stop being you and start being someone with an entirely different set of memories (experiences, learned skills, emotional responses) at the flip of a switch.

Bad assumption: that there is no room for diversity in a single strong AI.

The self is a masquerade. The self is better described as a federation of selves. The fact that you don't always make the same decision under identical circumstances means that you aren't just a monolithic unchanging self. The fact that you have options to choose from means that you contain more than one point of view.

It's entirely possible for a set of strong AIs, each with different points of view and goals, to remain hidden behind what you might call their spokesperson. As a result, said spokesperson could very well contain a diehard Led Zeppelin fan, depending on to what music it had been exposed and whether there was a corresponding positive emotional stimulus. And a die hard Rolling Stones fan, given a different set of memories. As well as an AI that had been exposed to a wider range of music without emotional conditioning, which would be better suited to describing the technical virtues and failings of each piece of music.

Questions?