Long after the 1 MB limit was put in place, Satoshi wrote:
>>The current system where every user is a network node is not the intended configuration for large scale. That would be like every Usenet user runs their own NNTP server. The design supports letting users just be users.
-July, 2010
>>It would be nice to keep the [block chain] files small as long as we can.
>>The eventual solution will be to not care how big it gets.
>>But for now, while it’s still small, it’s nice to keep it small so new users can get going faster. When I eventually implement client-only mode, that won’t matter much anymore. (note to readers, "client-only mode" refers to SPV mode)
-August, 2010
and in an email to Mike Hearn:
>>The existing Visa credit card network processes about 15 million Internet purchases per day worldwide. Bitcoin can already scale much larger than that with existing hardware for a fraction of the cost. It never really hits a scale ceiling.
So your explanation for his reasons for putting in place the 1 MB limit are not consistent. Others have said that he was afraid that someone would soon come out with GPU miners and be able to DOS the network with large blocks, so put the limit there as a temporary measure. Now that mining hardware evolution has slowed, and the mining ecosystem matured, this kind of threat is non-existent.