Because Part 135 IFR needs a lot of equipment and pilot hours to be legal.

Because it builds character. No in all seriousness just like dera said the smaller planes aren't certified to fly IFR not that I would want to the some of the 207's IFR anyways. You need to meet the IFR mins hour wise so they keep the 207's and such on a VFR basis.

So any ideas what to do with 400 hrs?)

Surveying and banner towing are really the only options aside from CFI with 400 hours, you still have 100 to go until your opportunities open up a little more.