Conifer Mulch Compost for Rose garden?

Hi there,

Its Autumn here in Melbourne, Australia. I have a row of conifer pine 
trees - medium size - dark green leaves. They are about 6 metres tall and 
are due for a good prune back. I thought of lopping off the top of the 
trees- mulching them including the leaves finely - and then using them as 
compost for my rose garden. I'm allergic to the pine leaves so I'm getting

tree pruner to do the job.

One old tree pruner however warned me that using fresh conifer pine mulch 
was a very bad idea and may kill the roses.

Is using conifer mulch for the rose garden a bad idea?