Protests are a consequence of a democracy that isn't.
If people had power, they would cast votes (on laws or representatives) instead of wasting their precious time walking around with little to no observable effect.
If the majority of a population think being gay or bisexual is a horrific thing, and are OK with barring these folks teaching jobs and the like, what happens then? If one doesn't protest and can't get jobs in positions that reach folks, what are the other options? Pretend you aren't gay? Pretend you only like the opposite sex? How in the world does this person fight religious messages saying this is wrong?
If you are in a country where such discrimination is OK, I don't think that the general population is going to look too kindly on the oppressed class protesting. There are already cultures where if you go against the majority opinion you can end up burning all the bridges to your family and friends.
There is often a large discrepancy between what people say that they believe, and what they actually believe. In a 'Christian middle-class family', it may be that everyone believe that everyone else is against homosexuality. The priest says it is a mortal sin, and no-one has said they disagreed. Secretly the kids might think homosexuality-as-sin is an disgusting idea, the wife might think 'of course gays rights should be respected', and the father might feel 'whatever, I don't care what people do in their bedrooms'.
In this example the personal opinion has shifted in favour of homosexuality, however the public opinion has not caught up yet. To break the stalemate of everyone holding their potentially-controversal-but-not-actually opinion to themselves, some external nudge might be needed. A protest might be what brings the topic up, so that peoples actual opinions can come forth.
Such outing can have ripple effects. Kid talk about their family fight-which-wasnt to other kids, and find out their families also are in support. Soon everyone in the church is collectively rolling their eyes when priest harps on gays. Eventually the priest picks up the vibe and stops mentioning homosexuality as a sin altogether.
The US, though? That's where I've experienced this stuff. It isn't always "kill the gays", just like it isn't always "kill the minorities".
The social backlash can be bad enough: I was 13 when some girls figured out I was interested in other girls. I sat alone the rest of the year and folks wouldn't speak to me. The high school I gradutated from (different school system) would not allow same-sex couples to go to prom together. I know of a school superintendent that tried not to hire gay teachers, as he thought a gay teacher turned his son gay. I personally identify as bisexual, but the options I had with women in the US weren't the same as men. A woman couldn't adopt my child, nor could we be legally married until recently.
As recently as 1998, oral and anal sex was considered sodomy by US military code. Guess what that means? Same sex sexual relations can get you dishonorably discharged.
And you are correct - few in the states look kindly on the oppressed class protesting. And it is supposed to be a right.
Protests aren't meant to persuade - they're meant to draw attention. Persuasion is a separate step in the movement. Look at BlackLivesMatter. The initial protests drew attention to issues of police brutality that most Americans had little knowledge of. Then, journalists contextualized the history of police violence and attempted to persuade readers. Protests also help frame a narrative, which make people more amenable to persuasion.
The problem isn't that the democracy "isn't". It's that people joining these protests are in a minority, sometimes a tiny minority, and democracies don't cater to minority opinions.
If people had power, they would cast votes (on laws or representatives) instead of wasting their precious time walking around with little to no observable effect.