Because, you need to reroute reset interrupt vectors.
PIC always jump to 04 and 08 on hi/lo int.
And you don't have anything there.
Generally that is bad idea, because you hijack interrupts from main code.
And that reroute you cant do in PBP, nor ASM at compile time. So you need to do it manually. Then you can reroute int vectors in main program, to some other location.
And all that is just bad.

What exactly you are trying to do. I know you are building bootloader, I have posted few on this forum.
It should be very easy, straight forward code... Not sure why you need interrupts.