Don't worry. All those asari ships and their crew still in working order will be happy to, ahem... help. Genetic diversity will be maintaned.
Yeah -
asari diversity. They could practically walk home within their lifetimes.
Well, you can look at that as Shepard finally seeing the end and actually wishing for everything to end.
It's not like Shepard hasn't expressed some suicidal thoughts through the game.
Only if you choose certain dialogue options (paragon tended to be more fatalistic throughout, renegade more determined). Some of my Shepards did, some didn't. It's out-of-character for the latter to spontaneously choose to manufacture their own death.
*after emerging from the beam*
Paragon Shepard: "It tastes like... dying!"
Renegade Shepard: "Just have to keep moving..."