Umm if I read your post properly your dissing not only on NIN but on all "not perfect" jobs? This is because we've never mentioned people playing "alternative" styles on NIN.

If you don't like E-Peen battles, You may not like the MMO genre.
This is horse sh!t. Having played over a dozen MMO's I can say with authority that while every MMO does have elements of e-peen waiving, I've never ~ever~ seen it as bad as in FFXI. You people take the concept of "perfection" to such an extreme that it discourages fun and fair game-play. Things get to the point that "if your not X job doing Y function, then you need to either level X job or jump off a bridge and die". You get people like wish who turn into obvious trolls and go around like their some sort of super "elite" player. You get sites like BG that become this cesspit of elitism, where they stand around all day and pat each others back and tell each other how great they are and how much everyone else sucks. In effect you try to mold the game for the 1~5% group instead of the 95% group. We saw this with the "WAR SAM MNK BRD BRD RDM" mentality that consumed the game so much that people were quitting due to lack of enjoyment / participation. Where content was being made accessible only to the 5% and not to the 95%.

This applies to this conversation because we're discussion possible tanks and their levels of effectiveness. To be a "tank" you need to generate enough enmity that the monster is focused on you and not on other players. In FFXI the most efficient method for generating enmity is hitting sh!t really hard really fast. There is also a hard cap on the amount of enmity you can have at any one point in time. This would lead to the logic that the requirement for tank should be to hit the enmity cap as fast as possible and maintain that cap throughout the fight. There is no requirement to deal the *most* damage, only to deal enough damage to maintain enmity cap. NIN is capable of doing this fairly easily, and it also provides shadows for damage mitigation / enmity conservation.

In short, there is absolutely ~NOTHING~ that a MNK *tank* would enable you to do over a *NIN* tank. When we start talking about kill times we're not limited by damage, we're limited by red / green / blue procing. For this end the MNK and NIN fights both take the same time, if anything the MNK fight would be longer as the MNK has no way of discerning red proc while the NIN can use Ei / Yu to get readings.