While this may very well be a problem within the startup community, I don't think this is a problem specific to nor originating in the startup community. Pizza, caffeine, desserts, beer -- these are all things that are easy to come across in many (most?) common social situations.

The office "christmas party" from the white collar mega-corp where you work is usually a big hit because of its free booze. After you win your game of adult <whatever sport you play>, the team goes out for pub food and drinks. When you invite a bunch of people over to watch <some important event>, you usually supply sandwiches, pizza, wings, booze, etc.

Heck, I can't remember the last time I've actively set up a meeting with someone that wasn't over a cup of coffee or a beer, and I don't own a startup or live in an area that even remotely resembles the common hubs for startup culture in the US.

People are just unhealthy, and in social situations, it is usually important to cater to the needs/expectations of the masses rather than the few.