I think it is a fair comparison. Brisbane is supposed to be a city with a population of ~1.8 million and growing while Sydney is a city of ~4.2 million people and steady. Sure Sydney is double the size of Brisbane but a city the size of Brisbane should be able to come up with some variety.
What is the problem? Is it all the years under Joh Bhelke-Petersen? I don't think I am wrong in my observation that the majority of people living in Brisbane go to work during the day and then return to their burrows as soon as the sun goes down but come out in droves on weekends.
I know I am repeating myself but in Sydney I would play competitive district darts on Monday nights, social darts on Wednesday nights, ten-pin bowling in a league on Friday nights, club golf on Saturday and social golf via an RSL social golf club on most Sundays.
The same type of organised (let's call them "community") events do not exist in the same scale Brisbane. I love my social events all through the week not just weekends. It keeps my mind occupied and away from scary, depressing thoughts.
So I will rephrase my original statement. The majority of Brisbane shuts down well before 9:00pm.
Agreed although I don't know too many people who want to spend their evenings with kids who are drunk or on a coughtail of drugs like crystal meth, speed, ecstacy, cocaine just to name a few.
Sorry but I'm going to drag this back O/T for one minute. Firstly to apologise for thinking you were 32. I have no idea where I got that from.
I also wanted to offer the suggestion of the Irish Club in Elizabeth street in the city and also I think the city RSL. I had forgotten the NSW club culture.
I would also mention that while my idea of entertainment, might vary slightly it doesn't include any of those drugs that you mention.
As a comment I come from Brisbane (QLD in fact Sunshine coast, BNE and CNS in equal parts) and my social life was exactly as you mention, varied and every night of the week. By comparison I've found Melb and Syd to be boring during my stints in those cities. My social activities were more social sport orientated, but all of those things you mention can be done in Brisbane, maybe not in the CBD. They even have golf, even Joh* couldn't get rid of that.
So I had touch footy, mixed netball, scratch soocer games every second friday, movies tuesday nights and of course, as you mention outdoors stuff on the weekends - go to the coast, a bike ride, touch footy practice, club rugby, more movies, picnic at kangaroo point, sunday session in a beer garden, AFL games (See mighty fitzroy play).
Also after the death of dad, mum has got into Bridge.
During the week this certainly didn't stop at 9 pm. I had netball games schedule for 9:30 and 10 pm even in the more popular comps. Yes, it is a different culture and that life is more about the outdoors. It is also about BBQs and visiting people at home. The other factor is that brisbane can be very clique-y. I love brisbane and it upsets me that you find in boring, because is not my recollection. I would dearly love to be able to show you the brisbane that I know, so I'm really trying hard to offer some useful suggestions.
Besides the Irish club and maybe city rsl, you could try the broncos club, they do a good show I believe. There are also lawn bowling clubs that work at night. Birdge maybe and there has to be darts going on.
but as others mention a lot of this will happen in the suburbs not the CBD, it is a spread out city. The 1.8 million you quote are definitely not in Brisbane city, that population is more likely to include the gold coast upto cabulture. There are heaps of things happening after 9 pm on a week day in that area that don't not involve young drunk things and drugs.
A couple more general comments - The valley under Joh* was run by his mates, not really a little asia. Sure china town is there, but the history of the valley is much more than chinatown or junkie's. Yes, gentrification sucks.
Shame about the testosterone, if that is happening there now, how many times I got refused entry for having a collar with the excuse that it is an alternative venue and with that collar your obviously going to cause fights like in the city.

So the tossers who made the valley seem to be having the chickens come home....
* please don't make comments about Joh, you perhaps only have an outsiders view and your comments are just that bit off the mark that it shows.