1. It's not the file system causing dataloss. It's combination of buggy drivers and incorrect application developer assumptions that are causing dataloss. The file system is working correct.
2. Ext3 exhibits the same behavior, as does all modern file systems. You have the same problems with badly designed applications with XFS or Btrfs, for example.
The only difference between Ext3 and Ext4 in this manner is that with Ext3 you had a 5 second window and with Ext4 you generally have up to 60 seconds. That is there is no difference in behavior if your system crashes in 4 seconds after a write.
3. Linux supports multiple different file systems and it always has. Your not dealing with Windows were your only choices in life are NTFS or Fat32.
Therefore if you want a OS that can benefit from the positive qualities of anything other then Ext3 then it's shitty policy to bend over backwards to support badly written applications because those developers never bothered to test on anything other then Ext3 or understand what the code they are writing actually does.
4. If you want your software to be portable at all to other operating systems, say OS X, Windows, FreeBSD, etc etc... then depending on the dumb-luck chance characteristics of a common configuration a nearly obsolete file system on a single operating system is not a good way to go.
5. Tso introduced a patch that helps mitigate this issue anyways.
Anyways. If you at any time complained about the lack of standards of banks that demand IE only, then what your saying now is slightly hypocritical. POSIX is a standard for accessing file systems and specific chance behavior of Ext3 isn't.