The issue isn't what Reid said when she was homophobic ~2010, it's that she lied about it to try to save face. She was recently outed as her blog was cited and she previously apologized for it. She was outed again for much harsher words towards LGBTQ, this time she feigned ignorance, claiming "hackers" must have made those posts. Even though she had hired "Cyber Security Experts" to get to the bottom of it. They found no evidence of any hacking. Though Reid still claims she "doesn't believe" she made those posts, there is no evidence that proves it, and her cyber security experts can't figure it out, either..
Everyone says something they regret later at some point in time. Should we hold Reid accountable for what she said? Absolutely. But since then, she's shown significant change in opinion when it comes to LGBTQ rights. That's something I would commend her for. That's courageous. It would be brave of her to simply own up to what she said back then and move on like she did before. Advancing this obvious lie is what tarnishes her credibility. The evidence shows she made those posts, too. Accept it, apologize for it (which she already essentially did, even though she claims she didn't make the posts..?) and move on. That's how you get past it.
But that's not what she chose to do. That's painful for activists and LGBTQ people to see and hear.