For those demonising parsers as the root of all evil... Try to think of it this way:

Think of FFXIV as 'going racing'. Much like in MMOs, logging and analysing data is equally common in some circles, FFXIV has many tiers ranging in both difficulty and competitiveness, clearing a 4 man could be compared to nipping down to your local go kart track (Just show up and enjoy yourself, anything more is just going to get you laughed at), whereas coil 1 is more on par with going club racing (Data here would be helpful, but you can be perfectly competitive without it), Savage Coil 2 could be considered to be approaching Formula One's level where unless everyone is extracting 110% and more, you're simply not going to get far at all. To play at the level the content asks of you, you need far more than can be gleaned from the combat window alone.

Also remember that not all classes are equal when it comes the ease of achieving 'good' dps. For example, bard is relatively simple, the difference generally comes from maximising activity whilst handling encounter mechanics and general movement, whilst summoners are much more subtle with effective cooldown usage making or breaking their damage output in a big way.

Back onto the motor racing analogy, parsing much like data logging in it's purest form isn't bad at all, it's not intended to be a tool for e-peen swinging, nor was it designed to break rules. Rather, it's there to facilitate self improvement and a better understanding of how various mechanics and abilities interact with each other. if this game ended at CT, then I would agree that this kind of data would be entirely unnecessary and I would be more inclined to agree with the anti-parse brigade. But it doesn't, so I don't.

On the flip side of the argument, one of the strong cases against having an open season on parsers is of course players using parser data to be abusive towards other players and I'll agree that that is a perfectly sound argument, however do not forget that SE have a pretty good track record when it comes to dealing with abusive players so far. You rarely see people calling out others due to fearing the ban hammer. As long as that continued to be the case, I highly doubt it would ever really be a problem.

Another shady area is of course a particular parser's little 'additional feature', and yes again I agree it's a bit of a step too far. Do note that it's only recently become a problem due to the overcrowding on hunts with the disproportionate and entirely uncapped rewards on offer. Also remember that this feature isn't something common to all parsers.

In short, the next time you read up on a strat for a coil turn, or watch an early kill video, or read up on advice on how to improve on your play style, remember that the majority of that information came from people using parsers. So when you are flapping your arms screaming that 'omg parsers need to be banned!!!1!', consider that perhaps, the parsers themselves are not the problem, rather it's the minority of people that use the data to abusive ends that are the issue here.