Should I be able to resign from a company for my own reasons for resignation?

I was 50/50 voting partners with a co-founder of my business. I am 22 years old and have never built a business but I came up with this incredible idea, wrote the original business plan, etc. My reason for resignation was specifically because of the fact that I had been compelled (by way of my other cofounder threatening to leave if we didn't continue with his way) to make strategic decisions that (now that we weren't hitting major deadlines) were clearly not the right strategic decisions being made. And now that I want to resign for that reason, and we are trying to get it in writing that that is my reason for resignation, he is telling me that it cannot be my reason for resignation because he believes he will not get investors to be able to invest in the company (in order for the company to continue functioning) if my reason for resignation is a disagreement regarding the strategy that he threatened me to follow in the first place. So, should I be able to resign from a company for my own reasons for resignation?