As someone (who like many) initially became acquainted with Neopaganism through Wicca, I certainly have a few insights I can share with you. I'd like to preface this by saying Wicca is a diverse branch of Neopaganism, so what I say shouldn't be taken as "this is how it always is."
There were two things that attracted me about Wicca when I first started looking into it.
First, was its emphasis on nature. Wicca is typically characterized as a nature-centered religion, which basically means the objects of worship or reverence are found in nature. Things like celebrating the seasonal/solar cycle and lunar cycle appealed to me. The idea of deifying nature itself was very new to me at the time because my culture teaches its populace that gods can't be nature or immanent.
Second, was the acceptance of the otherworlds, the idea of spellcraft, and the overall aesthetic of the religion. I'd had "spirit guides" for a very long time, but had no idea there was any sort of religious movement that not only accepted their existence, but encouraged people to cultivate those kinds of relationships. The idea of spellcraft (usually called magick within Wicca and Neopaganism) was also very intriguing to me, as before then I thought spells were just things you read about in fantasy stories, not something you could actually do. And, as a huge fan of fantasy, the aesthetic of wandering in the otherworlds and practicing spellcraft was very appealing to me.
Both of these things that appealed to me about Wicca are things that I have retained in my current practice, but Wicca was ultimately not where I belonged within the Neopagan spectrum. There was pretty much one main reason for this.
Although Wicca may be polytheistic, the principal manner through which it understands the gods is duotheistic or ditheistic. There are two main gods: the God and Goddess. Much of Wiccan worship and symbolism revolves around sex and gender polarity. This is masculine, that is feminine, yada, yada, yada. As someone who rejects the construct of gender entirely, that was simply unacceptable to me. To not mince words, I found Wicca to be inescapably sexist (because I find the concept of gender inherently sexist) and entirely too anthropomorphic (because it slaps sex and gender on to aspects of reality that honestly have neither) with its approach to the gods.
There were other things that didn't jive well too. The Wiccan Rede and Threefold Law never struck me as particularly sound ethical maxims, and I had no interest in adhering to them. The manner in which Wiccans do spellcraft and ritual was modeled on ceremonial magick and western occultism, which is a style I found that I didn't particularly like. Much of the Wiccan literature and overall flavor of practice is much too whitelighter for my taste, although in theory it doesn't have to be. I left it behind for my own brand of religious Witchcraft that could variously be described as Green Witchcraft or Druidic Witchcraft.