Taste is subjective and fleeting. The once lauded tastes of the 90s are now regarded as oh so dreadfully pedestrian by enlightened contemporary minds.You seem to have specific examples in mind. I have no idea what they are on this side of your skull. More specific language would be appreciated.
The crux of taste is rooted in celebrity worship and group think. Taste is a roll of the die and a hope that your vision resonates with those around you.
A lot of what is called "taste" is group think. Not all of it is, however. In addition to "taste" there is also Taste. A number of the hallmarks of Taste in instrumental music, like the ability to use slight modulation of rhythm to convey the visceral feeling of specific dance steps, are demonstrably cross cultural and enduring across generations. Many of the hallmarks of Taste in visual design (rule of thirds) have endured over hundreds of years. Note that these examples are rooted in the function of the human sensorium -- that's not coincidence.
This isn't to say that absolutely everything Louis Armstrong's contemporaries did still resonates today. It also isn't to say that absolutely everything the old masters painted resonates with 21st century viewers. But note how much of what Louis Armstrong and Michaelangelo did which still resonates and which contemporary artists still include in their practice. We now know from science that people are not "blank slates." This notion was just an ideological fiction. Our senses and perceptions mostly work in a particular way, and this is bound to give rise to Taste.
That said, you are mostly right, and our functioning as social animals with the ability to maintain ideologies as a group bonding mechanism also gives rise to "taste."
Taste is almost negligible.
If by this, you mean that the ratio of Taste/"taste" is frustratingly close to zero, I'd say you're right. Groupthink is agonizingly powerful, but that's only most of what there is, not all of it. (Sturgeon's Law)