I'm in full agreement with the original post. This is ridiculous that they can't accommodate this. I'll try to summarized what I have, and what I think is needed: (and I think is what the original post was asking for as well).
I always consider the 'ground' plane to be the X-Y plane. For some reason, Inventor seems to come defaulted to the X-Z (or something). I changed all of my templates so that the default view when starting a new part of assembly is oriented so that the Axes triad has X to the right, Y towards the back, and Z up. A CNC machine is generally set up this way (X positive to right). The, I oriented the view cube the same way (Top view shows as X-positive to right, Y-positive 'up'). Right-clicking on the View cube and choosing 'Options' allows you to set 'Default ViewCube Orientation' any way you want . . . "XY(+Z)" for me.
What is frustrating is that when I start a new part with my templates, the blank part/assembly comes up in a nice isometric with my preferred home orientation as described. But, then when I select "New 2D Sketch" Inventor automatically rotates to what it thinks the default orientation should be, so I need to click 'Home' every time.
Others described well the option to automatically start a new sketch on a particular defined plane, but that's not what we want. There should be an option (or it should just be default/baked-in behavior) that Inventor rotates to user's selected default View Cube orientation on New Sketch . . . .or, just doesn't change orientation at all.
Can we have this please??!