Because why not? "it's gonna be a fun hobby", "my local roaster is too expensive, it will pay for itself in 3 years", "I wanna try beans I can't find at my local roaster's"...
I watched a lot of videos to understand the basic principles, read a lot of forums and blog posts about roasting and the gene in particular, completely fucked up my first 5 roasts, tried half a dozen "recipes" before finding something that works for me 😅