Well that is ultimately up to the individual, their beliefs, and their definition of sacrilegious I suppose. After all, the word itself is defined as being an act that is the violation or profanation of anything sacred or held sacred. So, really it is defined by whatever religion you hold sacred, as any act that is outside of the rules or ideologies of that faith would be considered sacrilege.
Add to that the very broad scope of people, faiths, practices, and beliefs of the people on this site and, well, that kind of puts it a little beyond the ability to judge accurately. Suffice it to say that this is a resource for information and sharing of ideas, and a forum for communication and comparison of ideas and ideals so that everyone involved can grow in knowledge and (hopefully) wisdom.
Since Wicca is a religion it cannot, by definition, not be sacrilegious.
Wicca may not be the religion that you follow. It might even go against your specific beliefs. That doesn't make it wrong for everyone, just wrong for you. For those of us who practice Wicca, such as myself, it makes perfect sense and brings us a great deal of spiritual fulfillment.