You are definitely right to an extent, but take note that taking loan to expand an existing business is the real deal because you already knows what to expect and their is a higher probability that the business will be fruitful than when you are borrowing money to start it up, but it's not entirely wrong to borrow money to start up a business if you are paying back from another source, the real reason most people will Advice not take a loan to start up a business is because you don't know how the business will play out, if it's going to be successful or not, but if you are paying it back from another source, it's a risk worth taking in my own opinion, but the best possible scenario is if you are taking the loan to expand and existing business.
You're making a good point, there's a different between someone who already has an existing business but wants to take a loan to expand it and someone who's taking a loan to start up a business from scratch, starting from scratch is more riskier cause the person haven't had an experience and you never can tell if the business would be successful and how would he repay the loan if it's not successful but someone that wants to expand a business is already experienced in it and would know how to manage the risk and make sure the businesses expansion is successful so he'll pay up his debt. Anyways the major reason for this thread is concerning Bitcoin investment with borrowed money and I won't advise people to do that.