I fly domestic with them regularly, and over the last decade or so I've been impressed with their shift to a mix of more mature ladies and gentlemen, and yes, some of the men have been quite openly gay.
However, I've only seen a maximum of 1 or 2 out of a crew of say 4. The more mature crew seem to do a much better job, without the attitude that seems prevalent in the younger generations.

I flew international in 2016, and again last year, and saw a similar mix - although it was a larger cabin crew on international, and they came from different places.
On my NZ flight, they were pretty much all Aussies & Kiwis, but going to China I found a wider mix - some were Kiwi (including 1 gay male), others Aussie (2 more gay males), a couple of ladies with British accents, and a few mandarin speaking crew of Asian appearance, but probably born in Australia, as they had next to no accent when speaking English. The gay Kiwi was stationed in my area, and as the return flight wasn't all that full, we struck up a conversation every now & then. He confirmed that Qantas were open about hiring gay staff, and actively promoted equal rights for all, regardless of preference, and it was the first job where he hadn't been targeted by bullies. He also mentioned the rest of the airline industry, and a lot of the higher-end hotel industry are much the same way. Seems obvious now when you think about it.

I haven't experienced any rude behaviour from any Qantas cabin crew member. In fact, quite the opposite from most of them (regardless of which team they bat for).
The only thing close to what you experienced is when I've seen younger crew members being a little short/rude when it wasn't necessary, but they were stopped quickly by a more senior (and mature) member.

It must have been very unusual in your case. Maybe they were all trying to outdo each other to become the Alpha male of the crew? Were they younger guys or well over 40?