The bitcoin.com domain is owned by a person who hasnt updated the site for years and I believe people could be confusing that site with the bitcoin project. In fact I have personally seen that happen on many occasions and had to explain that no it isnt the bitcoin project.
I think it would be prudent to get the domain if that is possible. Are you able to contact the current owner of the domain?
This thread seems to have drifted a bit toward something like, "is .com too mainstream for the likes of bitcoins" but I agree with noagendamarket that it could be a liability for the legitimate bitcoin community if the brand were abused. I would chip in to a bounty to secure the .com domain for a group I trusted with the integrity of the community.