there is really only one manufacturer's boats that I loathe
I'm curious. Why do you loathe their boats? Do the shrouds pull out of the decks? Does the fiberglass peel off?
I'm mystified that some may consider SN to be biased toward larger vessels or more experienced members.
Not necessarily more experienced but definitely towards racing and larger boats.
I really don't see that. An experienced member may be more emphatic because their experience is often learned through hard knocks but I've never detected an arrogance.
I've seen people claim that you can't buy a good boat for less than $100,000. That statement is clearly absurd. But perhaps it isn't arrogance; maybe it is just stupidity. Now a person like this might be well versed on larger boats but their breadth of knowledge is much too narrow for the vast majority of sailing.
As for the notion that a larger boat means more experience I also have serious doubts about that. I have posted on boards where members were scared to death to sail out of sight of land but they attributed their requirement to have the largest possible boat under their feet to everything but fear. Others insist on a larger boat because they can't stand being inconvenienced. I'm sorry but being afraid or having to be as comfortable as possible doesn't make someone an expert.
Regarding smaller vessels, my wife and I are considering a significant downsize to a sport boat that we can afford to aggressively campaign. So you won't see a bias against small boats from me.
I'm not quite sure what you are calling "small" here but I suspect it isn't what I would call small.