it's interesting that it's in poor taste to throw a party for yourself ie: Engagement, Bridal Shower, Bachelorette Party. On the contrary, it is perfectly acceptable for one to host their own wedding and reception. Technically, it's still a party where you are asking people to come celebrate along side you, and most people do bring or send you a gift. This is not in poor taste, yet, you hosted the event.
Don't get me wrong I would never throw one of those parties for myself, but I am throwing my wedding/reception. I've never been to an engagement party with gifts, so I would not think it strange for someone to host their own wanting me to celebrate their intended union. I love parties! I'd definitely want to celebrate. And for a bachelorette party no one brings gifts to those, so asking people to go out and celebrate your "last ha-rah" is for some no more than asking friends to get together for dinner at a restuarant or a saturday night on the town.
I still wouldn't do it, but honestly I'm not seeing the wedding/reception that much different. Especially when, the bachelorette party not with standing, the guests are being treated to refreshments or a meal from the hosts. The hosts are simply asking you to celebrate.
