You can't chat up a dude in any other place than a gay bar, and a lot of people avoid gay bars. So there is a lack of an alternative. Most guys are straight, so whats a gay guy to do?
There aren't many other options. Even heteros use them more and more (I feel like 8/10 people from 18 to 30 use them at this point, in some countries), cause our generation doesn't really do well with the conventional methods of meeting people. We're all kind of... idk... unwilling? Scared?
Still trying to find the balls to make an account on one of them though. It really doesn't seem / sound / feel like my thing, but...
Apps like Grindr create an environment that provides easy and convenient access and communication with other members of the LGBTQ community, while such environments only manifest physically in places such as gay bars. These apps ease the difficulty of meeting other LGBTQ people in person, as this group represents a very small portion of our world population and the odds are otherwise slim of coming across someone who is: 1) LGBTQ, and 2) representative of your desires in a partner.
Most straight Tinder users I know treat it as a joke, whereas these apps are now a common tool for LGBTQ dating.