Opinion: Instead of discussing whether straight/cisgender people should be allowed in LGBTQ+ bars/clubs, we should be thinking about what can be done to make other bars/clubs feel more approachable to the LGBTQ+ community.
As someone who identifies as a gay, bi-romantic, cisgender male, I regularly spend my time in "the scene", and for me it's been a fairly liberating experience. Going to gay bars and clubs, for many people in the LGBTQ+ community, can be a very freeing experience: you can meet other people in the community, openly express affection to a same-sex partner and it can serve as a confidence booster as well as being a big part of someone’s coming out process. This is notably down to the fact that these venues are supposed to act as safe spaces, or at least "safer" spaces, for those that identify within the LGBTQ+ community; a space where they should feel free from prejudice and oppression and are able to be themselves regardless of their identity. Yet, the question of whether straight/cisgender people should be allowed in LGBTQ+ bars/clubs is considered by some to be a contentious question to answer. In my opinion, though, it really couldn't be simpler.
To deny entry to someone based on the fact they are a straight/cisgender person would defeat the purpose of an LGBTQ+ bar/club. These spaces are supposed to be accepting and welcoming to everyone regardless of gender identity or sexuality. It shouldn't make a difference if someone is present that doesn't identify as LGBTQ+. If you are looking to meet someone to form an intimate connection or relationship with, it can feel even harder to meet other people that are attracted to the same sex. Therefore, if you meet someone in a club you had hoped to pull, finding out they're straight is probably the last thing you want to hear. But that doesn't mean to say the club has been taken over by straight people, nor that all hope is lost that you will find another person to be intimate with. There's no scientific method of determining what a stranger's identity is anyway; you can't just assume these things so the only thing to be done is to talk to people! Not allowing straight/cisgender people into LGBTQ+ bars/clubs is not the way to go about making it easier for people in the community to meet.
This question is comparable to another ridiculous inclusivity question: can straight people go to Pride? Of course they can! These types of spaces are not supposed to be excluding people, but rather be an inclusive space for everyone. We call them allies for a reason: if a straight/cisgender ally goes to a Pride march then they are there to support the movement for greater LGBTQ+ equality, which is surely only a good thing. One thing I would say to straight/cisgender people who have never been to an LGBTQ+ venue/event and perhaps aren't as informed about the community as they could be, is that they should respect it as a safe space. For example, if you meet someone you know at an LGBTQ+ event and learn that they identify within the community, this is not your opportunity to spread that information around, especially not without their permission. Just because someone is attending an LGBTQ+ venue does not mean to say they are completely open about their identity with everyone. While some people that go to LGBTQ+ venues are completely open about how they identify, for others this is the only space they are able to be themselves. Some people may still even be learning.
Any place acting as a safe space for the LGBTQ+ community should not have to mean there are no straight/cisgender people, but that everyone present shares the same values of acceptance and tolerances towards everyone regardless of how they identify. In the case of an LGBTQ+ bar/club, as it should be anywhere else, everyone present should simply be there to have a good time whether that involves drinking, dancing, agreeing to make out with a cute stranger or all of the above. Instead of discussing whether straight/cisgender people should be allowed in LGBTQ+ bars/clubs, we should be thinking about what can be done to make other bars/clubs feel more approachable to the LGBTQ+ community.