Callisto
Hellenismos, BTW
What @JustGeorge said. I know nobody who is currently Wicca, but a few who were for a short period.
The reasons given already (accessible, magical, nature affine) were among the reasons my friends connected to Wicca. Additionally, Wicca is egalitarian, especially for the sexes. Goddesses and priestesses play a vital role in Wicca - in contrast to the patriarchal and misogynistic traditional religions.
The reasons to leave Wicca are that it has become rather inflexible (after not even 100 years), something which was also a reason to leave the traditional religions and the hierarchy that has formed.
Most of the ex-Wiccans have become Free Flying Witches, i.e. magical, syncretistic pagans without any tradition. Some went Asatru, one or two druids (though the English Order of Druids can be quite hierarchical, also).
How has Wicca become more inflexible?