Sticking with a manager only works if the manager is the right man for the job. That sounds like catch 22, in that we can't predict the future, but sticking with a bad manager is far worse than sacking a good manager (a bad manager is guaranteed to do progressively worse, there is always a chance a replacement will work out).
So how do we know if *this* manager is the right man? There is guesswork involved, and some of it is gut feeling and of course that is going to differ from person to person. The rest is going to be based on past performance combined with expectation. I'm going to ignore expectation, simply because any manager coming in would have been expected to get us into the playoffs, regardless of who they were (although expectation was certainly higher since Adkins came in, but on the flip side, I think most of us would be reassured by a winning streak or some good performances at this stage!).
I'm curious to find out what people are putting into the positive/negative columns? I'm guessing what you list here dictates whether you're in the plus/negative camp (to start with, feel free to add):
Positive (or at least; not negative):
Record with other clubs in this league
Record of bringing youth through (at other clubs)
Positivity (?)
Is happy to try different tactics
Isn't entirely responsible for the mess we're in; has had to work with other managers' players (although all managers have this!), and an AWOL board.
Was welcomed to Bramall Lane in traditional SUFC style: by having his best player sold from under him, money not reinvested despite promises
Brought Billy back
Quickly recognised Howard wasn't good enough
Finished above Wednesday with Scunthorpe, relegating them

The number of managers sacked previously has meant the board are reluctant to sack another (this is a positive for him. He's been lucky in some ways, I think in another season he'd be out on his ear already!).
Negative:
No getting around this.. performances.
League form/not meeting minimum expectations
Motivation: the players are called all sorts on here, but we know many are capable of producing more than they are doing under Adkins
Adkins came in singing "Everything is Awesome!", yet the sense of unhappiness/unease around the club is getting as high as it's ever been
Signings have been, for the most part, pretty rotten (this for me is the biggest issue, as we'll be having a clear out in a couple of months!!!).
Never seemed to get a handle on squad strengths and weaknesses/hasn't identified the type of personalities we need to sign/failed to identify our positional needs (until too late)
Substitutions often seem very strange, and more worryingly, rarely work in his favour
Tactical changes haven't (thus far) changed our fortune
Continuing to play players out of position when it hasn't worked out for them previously
Hero to zero (in the eye's of many) in half a season... quite remarkable really!
Doesn't seem to have any answer to pull us out of this malaise
Thought McEveley was capable of leading (nothing against the lad, I think some of the abuse he's got has been out of order, but he's not the right personality for captain)
He's not as media savvy as he likes to think he is (there are ways of dropping hints about what is happening behind the scenes without playing your hand)
His record isn't as tidy as some make out, he's been relegated a couple of times, and sacked twice (not revered by his last club, Reading)
Has arguably found success elsewhere with players who were already at the club (Law's players at Scunthorpe, an almost unparalleled number of talented youth at Southampton alongside a number of other players who were later sold to Man U/Liverpool/Arsenal) - certainly not a bad thing, although something he's been unable to replicate here.
We require a full rebuild, is he the man for this?? (this is in negative, because I think not)
General lack of desire in the team is a worrying trend. We get outplayed, outrun, out-muscled and outmaneuvered by clubs and players bought with 1/10th the budget/salary
Unanswered questions:
McNulty - the messiah, or a very naughty boy? (i.e. was shipping him out good or bad)
Has he lost the dressing room?
Has money been available and he's unwisely chosen to not spend it? (as indicated by both Phipps and McCabe)
The soundbites in interviews - they sounded shallow the first 50 times. Are his team talks like this?
Suggestions of a split in the dressing room, is he the sort of manager who can slap them into shape?