Because any decentralized system is going to have high transaction costs and scarcity anyway.
This is a meme that keeps coming up that I think just isn't true.
What other decentralized systems can we look at as role models?
How decentralized are they?
And why did they succeed when "more efficient" centralized systems did not?
The Internet is the most successful decentralized system to date; what lessons should we learn?
How decentralized is the technology of the Internet (put aside governance and the issues of who-assigns-blocks-of-IPs-and-registers-domain-names)? How many root DNS servers? How many BGP routers along the backbone would need to be compromised to disrupt traffic? Why don't we see more disruptions, or why are people willing to tolerate the disruptions that DO happen?
And how did the Internet out-compete more efficient centralized systems from the big telecom companies? (I remember some of the arguments that unreliable, inefficient packet-switching would never replace dedicated circuits that couldn't get congested and didn't have inefficient timeouts and retransmissions)
What other successful or unsuccessful decentralized systems should we be looking at?
I'm old-- I graduated from college in 1988, so I've worked in tech through the entire rise of the Internet. The lessons I believe we should take away is that a system doesn't have to be perfect to be successful, and we shouldn't underestimate people's ability to innovate around what might seem to be insurmountable problems, IF people are given the ability to innovate.
Yes, people will innovate within a 1MB (or 1MB-scaling-to-2MB by 2021) max block size, and yes, smaller blocks have utility. But I think we'll get a lot more innovation and utility without such small, artificial limits.