There's been a discussion over on Barbore about a new range of pre-prepared foam sauces called Airspuma, and what this means for cocktails. I made the point that it's the kind of product that could lead to a national chain (let's say All Bar One, for example) including a cocktail with a foam component on its menu, which would open that particular strand of mixology up to a new audience. But, thinking about it, we're not going to see foam cocktails in the mainstream anytime soon.
The drinks that you see presented at competitions, the cutting edge, experimental concoctions you see in the very best bars, these all represent a small section of the market. They're the drinks that will be included in programs 5, 10 years down the line, but they're not necessarily right for widespread adoption yet.
For things like foams, gels and airs, semi-liquid pearls and all the tricks in the molecular mixology toolkit, you can add another decade before they even enter the conversation, let alone become a part of a standard service. At the moment, it's hard to convince regular drinkers (the ones who stick to what they know, and it ain't cocktails) that making a mixed drink requires more thought than “lob it in a glass and give it a stir.” A drink with a foam component is going to be so far outside of their frame of reference that you may as well be talking about particle physics.
There will always be bars and bartenders working at the bleeding edge of innovation, and they do important work. Give it time, let the ideas filter out from those in the know to everybody else. Then we can talk about whether a premix aerosol foam garnish will damage the authenticity of a drink.