Earlier quoted context omitted.
How can flavor possibly considered an objective metric?
In the sense that alcohol beverages sit on your tongue and most have a designed flavor, of which there are many varieties to enjoy. But I suppose you're right, marijuana smoke does have a flavor, and you may prefer that to any alcoholic beverage. But granting that it's not objective, it still something one could point to (and I would) as a reason for preferring alcoholic drinks.
Most people looking for flavor aren't smoking. Vape products these days are designed with specific flavor profiles. I'm not talking about the strange mango/bubblegum/etc flavors, I'm saying most weed itself has designed flavor for extracts these days. In the same way that orange juice is a design flavor (manufacturers will work with the brand to combine sugar/juice/oils/scents/pulp ratios), most dab vape concentrates are reduced to their bare components then recombined to achieve a flavor profile desired. Want it more skunky? More piney? Sharper? Softer? It's all achievable and designed.
The industry has changed drastically in the last decade. Consider smoked weed to be analogous to moonshine when comparing it with alcohol. That's not a dis towards flower, but many products are just as heavily designed as a bottled beer or scotch is these days.