That the "gatekeeping" process seems to be working for me is not the same as saying it works in general.
My understanding of my gender identity evolved over a long time, with the bulk of that understanding solidifying in the last 3 years. During that time I turned to 3 therapists (2 individual, 1 marriage), 5 clergy persons (3 Congregational/UCC, 1 Unitarian Universalist, and 1 Soto Zen), and 2 clergy interns (Congregational/UCC) for support.
Work with the first individual therapist stopped when it seemed the issue I had brought forth, depression, had been solved. Part of that solution was when I determined that I was androgyne/genderqueer/genderfluid. I began working with the second therapist at the suggestion of the marriage therapist, as she felt my then-wife and I would benefit from having personal therapists while in marriage therapy. It turns out, the marriage therapist was right.
I had another bout of extreme depression (usually considered a mental health issue) that stemmed from the fact that I was in the wrong body. Discussing this with my second therapist led to me starting transition, a decision that I made and she supported me in that decision.
This therapist, the marriage therapist, and the Zen priest got me through what was possible the deepest depression of my life, after my then-wife said she wanted a divorce. I was on Craigslist and eBay shopping for a gun to kill myself. This, too, is typically seen as a mental health problem. The UU and UCC clergy and interns also helped me a great deal throughout 2011.
In my case, I think it could be argued that I had mental health issues. These issues were, to me, side-effects of GID.
But, that's just my case. It seems to me that there are as many ways to transition as there are people who transition. What works for some won't work for others. If I want hormones prescribed by a US endocrinologist, it seems I have to go through these steps. Likewise if I want SRS with a US surgeon. However, I have discovered that there are ways to get hormones online, and there are non-US surgeons who don't require the letters, surgeons who seem to be well-respected, too.
For the time being, I am choosing to follow the guidelines as described in WPATH's Standards of Care. That is my decision.