I'm going to be exceedingly fair here...probably wrongly. But I'm at peace with the expectation he'll be gone soon, and the season is over.
He gave us hope and pride. Which then he proved unable to deliver on, which turned us all towards anger and despair. However, largely due to the first season, when he was whispering sweet nothings in our ears and backing it up with results, he gave us a semblance of PRIDE back. Under Moyes and Kenwright we had stagnated. We were happy trying for cups, hoping for a 4th place finish, and being the 'best of the rest'. We are no longer there. We want silverware, and anything else is unacceptable. Which is precisely how it should be for Everton. 21 years without a trophy. We had every potential of learning to accept that we just can't and won't compete.
While Martinez is simply not good enough, he did, through relentless, grating, frustrating positivity remind us that Everton are winners, not also rans. Which is precisely why he isn't good enough for us. Too many were happy with 'punching above our weight' and finishing 6-8 every season. Now, confusingly, our expectations are higher. This is his positive impact.
The other way to remember him is that he simply is not a very good man manager, and he's utterly terrible with defensive tactics and should never darken our dressing room again.
I feel both of those are true. The dichotomy of Martinez: Creates hope and belief. Fails to deliver. Exits. Hopefully we show that pride and expectation and get someone in that can end our drought.