It would be a further sign of Israeli weakness and therefore a major security threat to the country were he to resign just now.
Whether he accepts responsibility or not, he will be booted out at the ballot box (or by some other means) at the earliest opportunity, so it makes no practical difference.
Perhaps, if the military operation goes “well” and the electorate begin leaning towards him again, he might be in a secure enough position to try to curry their favour by admitting a few of his failures.
He’s a fairly stiff-necked fellow.