I believe most day to day communication provides a necessary opportunity to give a motivational speech. Most people today are overwhelmed and they really need inspiration. Studies continually suggest that people thrive on recognition and never feel like they get enough.
Driven to Distraction
Add to this that technology continually tempts (or forces us) to take on a detached perspective in an attempt to avoid information overload and just maintain our sanity. Today we have an exceptionally low attention span; so anyone who can keep people's attention for longer than a minute have the power to propel change. Once sure way to get someone's attention is to talk about them.
As it is harder and harder to do, many people seek out ways to influence others. To communicate a message you can write a letter, send an email, tweet it out to your twitter followers or give a motivational speech. I would argue the only real way to be a compelling influence today is by delivering a personalized ( often one on one, although others can be present or involved, it adds impact) motivational speech.
Motivational speeches push ideas outside of your head into the world where they can change others paradigm. Most people don't see themselves as motivational speakers so they neglect this important medium to influence others. Also consider that when people don't speak up sometimes they seem aloof, disinterested or disengaged.
Great motivational speakers move people from being disinterested to interested in a subject. They take you on a journey and compel audiences to sit up and listen. Yet the more common motivational speech is not on a platform, delivered by a motivational speaker. It is the everyday opportunity to stop, notice, recognize and verbally appreciate the hard work, effort and skills of those around you.
Read: Give a Motivational Speech in 5 Minutes or Less