Vaccine Confusion

I am genuinely confused, please do not attack others opinions. I'm just a first time momma looking for answers. 
I know there are plenty who believe that the MMR vaccine has been linked to autism. Is that the sole basis for not using ANY vaccines? Am I missing something? If you believe there is a link, why not just avoid that one? 
Please help me understand. 
Update: I am not saying that I believe the vaccine has any credible link to autism. I plan to vaccinate my child. I am just trying to understand those who do not.