I would have as well, once upon a time. It's critical to treat people with respect if you want them to listen to your message. Abrasive or "telling it like it is" is also a roundabout way of saying "shut up and take my opinion at face value because I said so". It's not effective.

As I said earlier, I have a personal trainer and I've been lifting for almost 20 years (which I think is actually longer than you've been alive, no?). For all the times I've been asked "what's the secret!?", the most effective way to help people has been to shut up and let them talk about themselves, their obstacles, and their goals. THEN, and only then, talk. Too many talk, too many hear, but very few listen. If people know you will listen to them, they might listen to you too.