GOOD DESIGN IS HONEST
Honesty in today's society is hard to come by. We all lie about a lot of things. We may not think we do, but we do. To most, they're little white lies, though sometimes worse, like lies that hurt people without even realizing it. You can even get so caught up in a lie that you have to keep lying to keep your job, your loved one, or even your belief in yourself. Lies like what you ate that morning; 'I ate a banana and granola' instead of 'I had three chocolate donuts', to prevent people from knowing that you ate extremely unhealthily. Lies like this happen often throughout the majority of peoples' days without even thinking twice. We've become so unaware of our lies that it becomes an immediate reaction to lie about completely mundane things.
This is exactly the opposite of what you're after for effective product design. We've all used products that have lied to us and never was that a good experience. It was simply a let-down. When you pick up a phone and expect it to work well as a phone, but in reality it's convoluted, frustrating, and confusing, you connect the brand of that phone with an inability to provide what was advertised. And that connection can, often times, be long-lasting.
When we preach about honesty in the products we design, we're focussed on making sure that the product delivers on its' promise. You need to think about advertisements, as they're easily relatable. If a trash bag is advertised as the strongest, most durable on the market and you decide to try it out, only to find that it's weaker than products half its' price, you'll quickly conclude that that brand is dishonest. So, obviously making sure you create a product that delivers on its' promises is extremely important for the acceptance and longevity of your brand. It can be easy to lose focus once a project is underway and after you realize additional potential of a given product, but it's extremely important to remember the beginnings of why the product is even being developed in the first place.