What is the overall obsession with "Femshep"?

I don't have a problem identifying with women in fiction, and I don't role-play as myself in video games, so the gender doesn't really matter.

When I have to pick in a role playing game, I usually base my decision on the voice actor. I like Jennifer Hale and Mark Meer equally, so my Shepard gender distribution has been about fifty-fifty. Same with Dragon Age II, where both Hawkes (Nicholas Boulton and Jo Wyatt) are equally terrific. I preferred playing as female characters in Assassin's Creed Odyssey (Melissanthi Mahut), Dragon Age Inquisition (specifically the English voice, Alix Wilton Regan), and GreedFall (Cassie Layton).

In an RPG without a voiced protagonist, I tend to choose the gender based on customisation options. In Dragon Age: Origins, most of my characters are men.

I think the adoration of Femshep is not really an obsession. I think it's more of a frustration and compensation by the fanbase because male Shepard was the default option. Femshep didn't have a custom character model until ME3, and was also hidden from the promotional materials until the Femshep trailer of ME3. Jennifer Hale cried tears of joy when Femshep was included in the trailer of the legendary edition, likely because of how absent she was from most promotional materials before. So in short, I think it's a case where people are rooting for the underdog because people genuinely like Femshep and feel like BioWare didn't give her the attention she deserved.