You know, where I was growing up phone calls were expensive, so people didn't call in advance if they were dropping by for a chat. Cheap unlimited phone calls here have resulted in a culture whereby you absolutely, positively have to call in advance for the tiniest thing. My friends are always surprised when I do drop in without calling and Arrington thinks the practise is akin to breaking in. shakes head
Presumably you know the people beforehand whom you're visiting unannounced. That is rather different than imposing yourself on a complete stranger, for the explicit purpose of pitching your business.
Calling it a "break in" is unreasonable, but it is still a strong turnoff to me: it just smacks of desperation, and of focusing on the wrong things. An entrepreneur should be focused on building a great product that people want to use; then have TC or whoever else will cover you because you've got something valuable to show.
With the exception of a few close friends, having someone dropped by unannounced shakes my concentration for at least a couple hours.
The kind of work I do is like holding a house of cards in my head. I am glad to see the social conventions go that make people feel free to expect to come knock over my mental house of cards anytime they want, steal my valuable time with their petty small talk, and treat me like I'm rude because I'm not skilled at cheerfully pretending their intrusions are wanted while I inwardly curse the damage they did to my concentration.
Extroverts have had thousands of years to do things their way. I'm glad to see societal conventions shifting in a way that benefits introverts needs to have uninterrupted time to think.