People have actually no idea how to do business

I see so many people building their SaaS products/ services without actually having even the most basic understanding of the underlying fundamental business principles that would help them turn their SaaS idea into a functioning and profitable business. 

I see people building really cool stuff with SaaS. And I also see people building completely unnecessary and uncreative stuff. And what a lot of these people have in common is that not a single one of them has ever questioned whether there is actually anyone who needs what they are building, whether what they are building actually provides any real value that someone is willing to pay for. 

What’s even worse they don’t even bother trying to validate their idea first but instead dive right in and spend a ton amount of time, money and energy on building something that in the end no one is going to use. And then they arrive at a point where they have nothing to show for all that time, money, and energy they’ve invested, start questioning the validity of building a SaaS business and entrepreneurship overall, and get frustrated. 

Am I wrong? What are your opinions/ experiences with that?