He considers himself to be a failure, it's hard to disagree.
I've just skimmed over the captain list from the 50s onwards, in my opinion I would consider him the worst. The three you name, one saved us from relegation, one captained us for one season and saw us qualify for the Champions League and Weir was only captain for a season.
Nev also captained during a time when we actually had a decent team that bottled it frequently.
What about pre-50's though?
When someone like Tubey says he's the worst ever, that means he's worse than every captain the clubs ever had. We're talking over 100 years here.
Are you really 100% confident that Phil Neville deserves that tag? Can we really in all justification declare it to be so? Is there enough supporting evidence to saddle him with that?
What's more important? What carries more weight?
Trophies won
Ability as an individual player
Longevity
Popularity
Longterm effect on the club
Leadership ability
Work ethic
Setting an example for other players
What he did after Everton
Chip in with others where you feel appropriate
If you combine those factors all together, does he get the lowest score?
In your heart of hearts, above every single other captain, is he the worst?
Is that fair? Has someone like Tubey really thought about this in enough detail to fairly to bestow such a title on Neville? Or, does he just hate him so much that's indulged himself in some hyperbole?