Why does this owner insist on doing owner financing??

[Sean Rhodes]

So I still haven’t purchased a property yet. I am pursuing a 3/1 for 50k right now. The homeowner doesn’t want me to finance with a conventional loan through a bank. He is insisting that I just finance through him at zero interest. That’s sounds great but there’s only one problem he wants it paid off in 4 years. So the place rents for $900 a month. So even in I put 10k down finances over 4 years that leaves me zero profit until the property is paid off. So my question is what reason or reasons would he have to not want to deal with my bank?? Is this a normal thing? Any advice would be greatly appreciated. Thanks BP