Yes there are challenges with adoption. Limiting the transaction capacity will not help.
It is a very stupid argument. Saying that current block size is limiting adoption is like saying a place is not attractive to people because it's overcrowded...
If only 3 people can send a transaction per second, then how do you expect 50 people to send a transaction every second (this is roughly 2.5% of what Visa does)?
The current 1MB limit makes it so roughly only 3 people can send a transaction every second (it has a limit of 3 ~tps depending on what assumptions you make regarding average transaction size)