yeah, but as stated by the Chinese miners, they don't have superior connectivity. in fact, it's lower connectivity. thus, how can these largest 5 miners of all be a problem to small miners?
I'm not going to comment on the specifics of some Chinese miners and what connectivity they specifically have, between each other and with miners outside China. I also don't think it matters much and find it hard to believe you think that matters. In a year or a few years the network might look entirely different. But there will still
always be a range of connectivity (and other resources for that matter) available to miners. That is the more important issue.
The term "anti-spam" means exactly preventing abusers from submitting more volume of activity into
the system as a whole than
the system as a whole can handle. That "system as a whole" includes a large (ideally decentralized) network that exists over a wide range of geographic, economic, and technological constraints. Again I fail to see what improvements have been made in ability of the system to absorb spam, aside from relatively modest improvements in the underlying bandwidth, storage, etc., since 1 MB that would justify an 8x or 20x increase in that limit.