What is the issue with Titan levels?
If your Titan dies at level 6 to an enemy level 6 Titan, you're basically doomed if you have to start over from scratch.
You've already got the enormous cost to cover, then the build time before it can get back into the fight, and now you guys want it to have to build its levels back up too?
I understand Titans have been really hyped up, but to have the death of your Titan be the end of the entire game is just ridiculous. They are not the central element, just a really cool and powerful feature. Having the entire game revovle around the survival or death of your Titan is not logical, and by allowing it to be rebuilt with its levels avoids this problem.
Need an explanation?
Ok, TEC Titan crews evacuate in escape pods before it explodes and rejoin in the new Titan.
Advent ressurect their crew in the same manner they can ressurect capital ships.
Vasari collect Nano-probes from the debris of their destroyed Titan and download all of the combat data into the new Titan and the crew.