What I learned is, my time is mine to protect and my skills are mine to dedicate where I see fit. Noone can oblige you to spend these things on what you don't want to.
People will always blame others for their lack of application. If they were true entrepreneurs, they will find a replacement for you.
But you are unique that you want to leave what is really a pet project (I've been in those too many times) and build a real business. You should!
Don't worry about what others will think, you can't control that.
A start-up is about bringing something its founders are passionate about to market. Anyone who thinks a start-up are a way to make money, are in start-ups for the wrong reasons. This sentence has failed start-up all over it.
The mindset that also comes with this idea generally leads to alot of burn out for those passionate and those who are feet up lets get rich with minimal effort. Which is was the fate of my start-up experience. 3 of 5 founders were passionate and hardworking, and 2 of 5 considered it a 'side thing' contributing much less (and even nothing when half-assed). When time came to find buyers to start cycles of improving the product e.g.'fitting the niche of our product', things fell apart. The same 3 of us called out that we are failing and don't see a path, and the 2 others completely did not see the death of the company/idea in front of them. We had majority and dissolved the company.
Maybe that my comment is pessimistic, but from my perspective start ups are an experience in failing.
The difference here is, if you choose to continue failing with these 'friends/cofounders' or make a call it quits. 13 months is a short life of a startup, but really this is the decision that you and only you can make. No one but you has the perspective and knowledge to make such a call.
Do you have paying customers? If so, that's not a bad start. Do your potential customers pay to solve the problem you are trying to solve? That's also not a bad start.
Have you considered hiring a consultant to help solve the problem, or to be the bearer of bad news (not having a clear understanding of your customer or the market)? I've helped people / companies figure out their target customer and what would solve their problems. Feel free to reach me at helpthingchat a.t gmail dot com if you'd like.
As to leaving, you can find the best way to frame it, and then do it. If they're really your friends, they will accept it. If not, who cares what they think?
The startup is about to die and you guys are pointing out the cause of death, googling shit, and already divvying up blame inheritance? Get out there. List your assumptions, meet people, try to get paid, get told your product sucks, get proven right or wrong, repeat.
>I would like to leave, but I don't want to be the one getting blamed, when the company finally goes bust. How can I handle the situation?
Which situation? Leaving or making saving your startup? If you'd like to leave, just leave. Just ask yourself if you've given it a real shot.
This takes time but the key is that all of you as cofounder need to make this a priority. I literally was thinking who the heck is my target customer today and I have been running a bootstrapped company for almost 6 years BUT the point is that you have to constantly refine that as needed.
Honestly, if you cofounders don't understand that it is all about identifying the market and the whole "product market fit" thing, it will be over anyway.
Would this blame matter because of your friendship with your cofounders? Or does their blame affect you in some other way?
You now have an option to (1) do what's right for you, and (2) potentially have some friends at the end of it. BTW it's not guaranteed that you can have either of these, let alone both.
If you are convinced that you want to leave, I think the best way to phrase it is "I no longer believe that the direction we're headed is the right one. You deserve a co-founder who is all in and believes in the mission. Even though I know this will be painful for everyone, the best path for the rest of you is if I leave now." Expect to give up most or all of your equity position, and maybe stay working a little longer than you'd like to get things wrapped up and in a good place to hand off. Also expect that this won't work and everyone will still be mad at you, but you'll learn a lot and your conscience will be clear. Maybe someday your friends will stop being upset and will realize that you were right, and you can be friends again. No guarantees though.
Best of luck to you.
This would likely be moderately illegal if done at a stage that the equity is demonstrably worth something (e.g. Eduardo Saverin's FB situation) but I don't think it would be much of an civil/legal issue before the startup had any demonstrable financial value. I could be wrong. And people will diverge widely on how they see the moral/ethical implications of this.
After spending a year building the product I would hate to walk away.
The actual potential market size may not matter. It is never a great idea to build a business from the top down. Instead, build from the bottom up by seeing if you can sell your product to whoever you think is the customer. The true test is right there. If you cannot get all of the stakeholders to the table due to needed partnerships, it provides another precautionary red flag.