I had asked this same question somewhere when I disassembled my Shadow 2 Compact the first time. From what I was told and it sounds logical, the tail is present to capture the hammer spring and keep it from rotating. Like I said, it sounds logical, but is it necessary, I don't know. Mine was a pain to get back in the first time so rather than just cut it off, I straightened it out a little at a time until it was much easier to install. So far so good and assembly is much easier now without that drastic curve on the tail and magazine still drop free. I got a host of reasons for the curved tail being present when I asked about it, but only one made any sense to me.
Rick H.