That said, many times there is no negative reason why a seller decides to put their property on the market and often I am permitted to disclose why. Most often it's for simple reasons: after 10 years, they want to move onto something else; or they are ready to actually retire (this is just a pre-retirement JOB); they want to move closer to family with grandchildren; they have to care for their parents; or simply, they've done what they wanted to with the business and realize it's ready to be taken to the next level and that's best left to a new buyer. Most of the time the reasons aren't negative, though we realize that not disclosing might force a negative assumption on the part of the buyer. Naturally if there's a divorce, illness or financial reason, these are very personal and usually sellers do not want to disclose too much of their personal lives.
So, the next time you (buyers) don't get an answer that satisfies your question "why are they selling?", don't concern yourself too much with that, focus more on if it's a good business model, the shape the property is in and what you could do with it. This is when having a buyer broker with experience comes in very handy.