So what if the 8Mb pre-set limit starts to be taken advantage of? That's why pre-setting a limit so far from the original is considered radical change by many. It has never been tested in anything as large as bitcoin.
Actually it has been tested before. When 1MB blocksize limit came to effect in 2010 the average blocksize was around 0.0003 MB. So only 0.03% of available blocksize was in use. With rise to 8MB that ratio with current usage would be 5%. So situation would be relatively equal to mid 2012, when 5% of 1MB blocks were in use.
Can you give one good example how 8MB limit could be taken advantage of?
I don't think there was anyone with the interest to stress test bitcoin's transaction logs back in 2010 among the then tiny userbase. We can't be sure about what could have happened if such a stress test would be performed with a 8Mb limit.
Edit: It's also not just about stress tests. There are more issues that I think increasing the block size blindly based on pre-set dates for doubling can be dangerous. In his '
Scalability Roadmap' Gavin justifies his views by saying that: "
But 50% per year growth is really good. According to my rough back-of-the-envelope calculations, my above-average home Internet connection and above-average home computer could easily support 5,000 transactions per second today."
Basing such decisions on Moore's and Nielsens law leaves out large parts of the world, which is probably why miners dislike bitcoin XT and vote against BIP101.