Extrapolating? Sounds like a job for Randall Munroe! http://xkcd.com/605/
Lots of small files isn't bad on its own. In fact, it's downright common. Ext4's design does consider this case and makes these operations efficient.
The problem with small files is data consistency. If the application requires a file hierarchy and associated buffers to be on disk before continuing, then a call to fsync() is required (even on ext3). Implicitly syncing on every small file will kill performance, so don't do that.
Ext3 doesn't write out immediately either. If the system crashes within the commit interval, you'll lose whatever data was written during that interval. That's only 5 seconds of data if you're lucky, much more data if you're unlucky. Ext4 simply made that commit interval and backend behavior different than what applications were expecting.
All modern fs drivers, including ext3 and NTFS, do not write immediately to disk. If they did then system performance would really slow down to almost unbearable speeds (only about 100 syncs/sec on standard consumer magnetic drives). And sometimes the sync call will not occur since some hardware fakes syncs (RAID controllers often do this).
POSIX doesn't define flushing behavior when writing and closing files. If your applications needs data to be in NV memory, use fsync. If it doesn't care, good. If it does care and it doesn't sync, it's a bad application and is flawed, plain and simple.
"In response to purely speculative figures announced in the press regarding the number of downloads and the price paid for the album, the group's representatives would like to remind people that, as the album could only be downloaded from the band's website, it is impossible for outside organisations to have accurate figures on sales...The figures quoted by the company comScore Inc are wholly inaccurate and in no way reflect definitive market intelligence or, indeed, the true success of the project."
The band, naturally, didn't offer any data of its own to offset comScores, but then it's probably good for business to keep everyone guessing.