Of course you love your family, friends and co-workers (some of them, at least), but in the context of (your) business their opinion is very tainted. Let me explain better.
If you are embarking into the tough world of Startups, and you leave your safe and secure job to try to create something new, usually, the first thing that a reasonable person would do is to validate what he or she is going to do. And who is better to ask them the people around you? They are right there.
$&@#... that is you falling into a pit.
You asked the people that like you the most and are probably most afraid of offending you, or shattering your big dream. Why would they do that? Maybe you do have a couple of honest friends that will tell you the "truth", but that still is useless. Why? 'Cause they are not your customers!!!
Repeat 3 times: Ask the Customers! Ask the Customers! Ask the Customers!
When you hear your friend Mark telling you "this is the most brilliant idea I heard in a long time", or when your Entrepreneur Aunt Janice tells you "you've got what it takes to make this idea into a successful product" think twice. They might be experts, they might know the field, but are they your customer? And they can't say they will buy or use your product, you have to be sure they will.
People can say whatever they want, but once you ask for an upfront payment for the product to help with the R&D effort, if they don't put the money down, they are not your customers.
Now, on the context of keeping you motivated and support you during tough times, having the comforting words of Family and Friends supporting your idea is very important, but that is that. It won't help you get more customers if your product doesn't solve their needs.
I'm the Co-founder & CTO of 
