"last changed / last modified" timestamps reset at restart

Just trying to participate in the WTH stuff.
Something that’s been on my mind for a long time, but not really been a show stopper thus far, more of an annoyance:
Why the heck are the “last changed / last modified” timestamps reset at restart?
If a sensor gets updated 1 day before HA restart, the last changed / last modified timestamp is automatically adjusted to the time HA restarts.

Duplicate of What the heck is with the 'latest state change' not being kept after restart?