Funny you should ask-- I recently wrote a blog post about this topic. Here's a quick summary of my thoughts:
The problem isn't avoiding the bias that comes with gender, it's ensuring that your user personas are backed up by site statistics and target market demographics, and understanding how gender actually affects UX (which may be contrary to our own suppositions). One of my favorite little tidbits of information is the importance of font choice when it comes to men and women.
In my opinion, the only time you should strip out gender information is if your site's statistics and target market demographics are truly gender agnostic (IE close to a 50/50 split between male/female visitors, and a product that is relatively equally consumable by men and women). For instance, if 70% of your site visitors are male, or if your building a site for, say, a vasectomy clinic, your UX and UI are likely going to be targeted towards men. One of the gender-specific aspects of UX design is the use of color schemes versus images to draw the attention of a particular sex. As men tend to favor vibrant color schemes to eye-catching pictures, you'll likely build your site with a dynamic color palette.
Lastly, don't forget what user personas actually are-- a way to personify the user, so you're designing and problem solving for an actual person rather than the faceless, nameless "user." Your work is more personal. You feel like you’re connecting with and solving the problems of actual customers.
After all, isn't that why we exist in the first place? To solve the problems of actual users?