Actually, this is what I call a controlled drilling. If the back ends are snappy and the heads are drying up it's a good layout. Last year we had a sub that was just killing the lanes all night long. He was throwing a xxx factor drilled with the MB to the left of the thumb, cg at midline and pin above and to the right of the ring finger. I have an X-It (shiny) drilled this way and although I rarely use it anymore I did throw it last year and it was my savior in many a 3rd game in league. However, if you're expecting a skid snap,or, heavy midlane kind of reaction this is not the layout to use. A friend of mne who was a touring pro at one time just began drilling some of his equipment with the thumb drilled right through the mass bias. The reaction is similar to your layout in that it produces a very smooth, elongated arc.
Obviously though you're not happy with your balls reaction and yes, it most likely is the layout. Plug her up and try a more conventional pattern geared for the reaction you desire. There's a ton of info on the web to assist you in determining what layouts might suit you best.
To say drillig the MB to the left of the thumb is wrong is misleading. It all depends on the coverstock,lane condition and your style.