Is it because they are unbanked?

There are some folks that are not very tech savvy or un-banked who paying in person or in the mail just works better for. 

For anyone struggling to get financed, I have a friend who runs a company called unbankable and it might be a good fall back for you. 

I do think that all of my unbanked tenants have smartphones that would be capable of having paypal on them. 

But they also can include tenants who are 'unbanked' or 'minimally banked' or just prefer to pay via this method.

The unbanked problem is real.

@Stephen E.As you see from the back-and-forth with Thomas S. unbanked individuals are far more rare in Canada than in the U.S.A. as banks are required under law to provide an account to any citizen who wishes to open one.  

Its not like you operate your life out of another person's bank account (unless you are one of those "unbanked" individuals). 

My local contractors in Phoenix AZare "unbanked".

We've done 100% CLTC (combined loan to cost) like this with our own funds before when the deal was completely unbankable but we had a relationship with the client and understood that we could broker the perm debt easily once the property was ready for it.