Well, insurance, as stated by CR several times, will be one of several minor expenses in game, as will landing fees, trade fees etc., so LTI is not really THAT important. There's been a lot of debate on the subject of LTI and my opinion is that it's not really that big of a deal. Some people want LTI just so they know their beloved purchased ship will be there forever and never have to bother with remembering to pay insurance.
I wouldn't necessarily pay extra for LTI, but choosing between a ship with or without LTI at the same cost, it would be a waste not to get it.
Also, when the PU finally gets here, less people will want to crash into your ship, knowing they'll have to wait for their own ship to be replaced by insurance - a time penalty that will increase each time you destroy your ship in a given period.
0.02 UEC
TL;DR :
LTI is not important (to me) unless it's free.
Also, waiting for insurance reimbursement will deter kamikazes.