Something I find interesting about the different model train scales and gauges are the different cultures that seem to exist in each. Some of these are probably related to the size of each scale, but size doesn't explain all of it. Take N Scale - from what I can see, the dominant culture in N Scale is big, modern equipment. That kind of makes sense because N Scale is the only scale that lets you model big, modern equipment somewhat realistically in a reasonable space. Given the small size, imaging what you could do with a branch line in N Scale - your model of SP's Jawbone Branch could suddenly look spread out and desolate just like the real line was. But... there's almost no small steam available in N Scale, I guess because the vast majority of N Scalers have no interest in it.
HO Scale has a lot of diversity - it's pretty easy to get anything from the earliest steam to the most modern diesel locomotives. The big thing in HO Scale seems to be fidelity to scale - not just accurate models, but good scenery, weathering, and "prototypical" operation. Simplicity seems to be frowned on. It's almost like you don't have a "real model railroad" unless you have an overly complicated track plan and/or an "official" operating scheme in place. HO is almost ALL scale, and lots of people in HO like to build kits or scratch build their equipment. There's almost NO "toy train" activity in HO, and anything that even hints at having toy roots (i.e. 4x8 layouts) will get a lot of derision from self-proclaimed experts.
S Scale is kind of funny. Don't get me wrong, I love S Scale. From reading the forums though I get the impression that the most enjoyable part of the hobby is forming a strong opinion and then denigrating or questioning the intelligence of anyone who disagrees with that opinion. If you don't believe it just try asking questions about American Flyer in a 1/64 "scale" discussion group (to be fair, some of the Flyer guys act the same way, but not as bad as the rivet counters).
When I got started in O gauge, the first two things I noticed were that (a) anything goes (high rail, tinplate, 2 rail scale, 3 rail scale, standard gauge, etc) and (b) O Gaugers are mainly into running (as opposed to "operating") and collecting trains and not so much into building lits or scratch-building. I guess that's because the main thing in O gauge is to have fun with your trains:) The second point confused me a little though. O Gauge has a HUGE pick of reliable, inexpensive locomotives and rolling stock that are perfect for kitbashing, and almost no one takes advantage of that fact. Not that their's anything wrong with that, I just thought it was a little wierd when I noticed it.
So, in a nutshell...
N Scale - big, modern equipment because pretty much that's all that's available
HO Scale modellers take their modelling pretty seriously
S Scale is being ruined by rivet counters. No, it's being ruined by some people's insistance on maintaining compatibility with outdated American Flyer equipment. No, it's being ruined by a few people demanding over-detailed, complicated, fragile "scale" models. No, it's being ruined by the continued existence of HiRail wheel flanges and "lobster claw" couplers. No, it's being ruined by blah blah blah...
O Gauge is mostly about having fun with trains.
I think moving to O Gauge was a good choice:)