B1 is a non-immigrant visa; you need to convince them that you are not going to attempt to immigrate.
But in case if it is possible to legally immigrate with B1, then what's the problem?
There are certain visa classes that are considered "dual-intent"[1], meaning that you can have the intent to immigrate while obtaining a formally non-immigrant visa. One such visa is the K-1 fiance(e) visa, which allows one to enter the United States for the purpose of marrying one's US Citizen fiance(e) within 90 days and subsequently applying for an Adjustment of Status (i.e. green card). The B class is not one of these, so you need to overcome the immigration / CBP officer's presumption that you intent to immigrate[2].
OP: Note that you are free to reapply for the visa; make sure you read the instructions on the form and fulfill the evidence requirements as much as possible.
1. http://en.wikipedia.org/wiki/Dual_intent
2. http://en.wikipedia.org/wiki/B_visa#Requirement_to_overcome_...
My bad luck was that I had a new interviewer who was extra cautious, understandably. He was in a doubt and went to speak to the guy in the next counter, and came back and said no. Which is a little screwed up because the guy in the next counter didn't even speak to me!
But there's no scope for an appeal, so the only option I have is to reaply and this time take some document as evidence and hope I have an experienced interviewer.
Fast forward a week where I came back with everything they wanted and a notarized letter from my parents, and she let me in (while still seeming to be quite pissed about it).
I would look at the evidence they want to see for ties to your home country, and post what you can gather to visajourney.com . They'll give you some suggestions on ways to improve it and/or tell you if they think it's enough. (Good people. If it wasn't for that forum, I may not have been approved for a K-1 and may still be living in Canada.)
A business accelerator doesn't really fall into any one visa category well. Is it a 2-3 month "business meeting" (i.e. B-1), is it educational (i.e. F-1), or even a "short course" eligible under a travel visa (B-2)? All of the above?
The reason you got denied is as it says, and while you can re-apply providing more evidence it will be an uphill battle. You just have to show WHY you'll be returning home (e.g. family, a job, other obligations)? By any chance did you list yourself as self-employed, rather than an employee of your own company? They hate self-employed people and often treat them as "unemployed."
Silly me, I didn't see that before the interview. Anyways, my interviewer was new and had no idea what an accelerator was.
What I am doing now is interviewing in another city, with the same application, albeit with added true information that would support why I want to come back, which I honestly do in the short term as my parents are unwell. The city I interviewed in first has almost no startups, so they have never encountered a situation like this before. This time I am interviewing in a city that has a history of sending startups to US accelerators including YC and Techstars.
Let's see, I am interviewing this week. Taking all documents including my parents medical documents and a printout of the page above. Fingers crossed!
a) attending meetings, b) Solicit sales or investment c) Make investments or purchases d) Interview or hire staff, etc etc.
As you can see the line is very thin between whats allowed and whats not.
The problem is that there's no "directive" as such, so a lot depends on the interviewer one has, because it's so subjective. Mine was new and had never heard of what an accelerator was. He thought it was an MBA!
But there's no scope for an appeal, one has to reapply and pay the hefty application fee again!
Oh, you play videogames professionally? Have a Visa!
Oh, you are starting a business? Our economy's bad, but we like it that way. Starting a business might change that. Why don't you learn to play League of Legends or become a fashion model and then try again?