Personally I do not do well with strict routines. They grate on me and make me feel tired and contrary because I don't see the point or value in having to do things at specific times when the important thing is usually more just that it does happen not precisely
when.
I dislike the feeling of obligation and need to conform or submit to an outside system which is created by making a schedule - even if it's a schedule I came up with myself. When things have to be done at a certain time I feel pressured and this feeling distracts me and detracts from my ability to actually do whatever it is. Feeling like I'm 'supposed' to do this right now vs. I 'want' to do this right now makes all the difference in the world, the first drains my energy and makes me irritated, the second boosts my energy and makes me feel like a living being, or a competent force to be reckoned with.
I also find that things tend to go much better for me if I do them when the proper mood or 'inspiration' hits, but since I can't dictate when that will happen, schedules don't usually coincide with it. I am much more productive/effective/accurate/faster etc. when I get hit with a 'cleaning mood' or a 'find out information mood' etc. By saying I need to be in the mood for something doesn't necessarily mean just things I LIKE doing, instead it means when I sense that I am in the correct mindset to do that specific thing to the best of my ability, and/or that I am currently experiencing stronger than normal internal motivation to accomplish whatever it is whether it's something that needs to be done or something I want to do. I'm not always in the mood to do things I generally 'want' to do, just as I'm not always not in the mood to do things I don't like doing. When I seize the moment of inspiration, insight, or motivation I both DO better at something and Feel better about myself for having used that inner spark. Thus I seem to be at my best when I have the freedom to do things at the right moment for myself, rather than trying to 'force it' at a specific time.
For example, I may plan to have dinner at 6, but what if I'm starving by 5:15? Wouldn't it be better to eat when I'm actually hungry than try to continue in my weakened or distracted or irritable state for the sake of preserving some schedule? What if I plan to work on some creative project after dinner but the inspiration just isn't there so I waste my time making stuff I'm just going to scrap later, when maybe I should have taken the hint and done some other thing during that time which didn't require creative inspiration and then when it does strike later on at midnight if I go ahead and sieze the moment I may create something really great, whereas if I ignore the inspiration because it doesn't fit with my pre-slotted time for it I'm going to miss out on the productivity it could have granted me.
Additionally I find that positive feelings are a source of energy and focus for me, so I need to cultivate them in order to do my best 'work'. Having a sense that I am personally directing my actions (rather than acting puppet-like under an external plan) cultivates feeling good about myself and having a sense of accomplishment, and this in turn generates more personal drive and focus to keep accomplishing things.
I think my issue with Schedules is that they often don't seem to recognize that specific situations call for adjustments. Such as, it may often be perfectly fine and doable to arrive somewhere at a certain time, but on specific occasions other factors come into play making it less than ideal to stick to arriving at that time and it would be better in the larger picture of things to change that time. Allowing for specific circumstances to be individual and different from eachother is to me very practical and realistic and I see strict schedules as a hindrance to practicality. When the schedule itself seems to be more important to someone that what is actually being done I feel like it's putting the cart before the horse as the saying goes. The things that need to get done don't exist for the sake of filling out your daily planner, your daily planner exists to help with getting things done but it's a hindrance if it prevents you from adapting to the needs of actual situations in real time. A schedule is like a theory or an ideal, essentially; expecting it to always play out perfectly is impractical, and making a fuss when things happen a few minutes off is, to me, rather ridiculous. 'whaa! my pretty schedule broke! how dare anything operate outside my will and control! whaa! the world isn't playing by my rules!'

(I'm thinking this is a bit Te-ish criticism but towards a normally Te-ish thing, hehe)
Now, I will grant that I
can benefit from working with minimal or flexible schedules, because I can easily loose track of time or become distracted despite my best intentions to take care of things. Often I can manage to not get around to certain things for a long time, even if I am accomplishing other things of importance, and thus a schedule can help remind me of things that I need or want to do. And schedules are helpful for coordinating with other people, since our personal 'moods' to do things probably aren't going to coincide naturally on their own. So there is Some value in schedules. I just prefer to know that when I need to adapt a plan, I can do so, rather than feeling locked into something that turns out not to be the best time for whatever it is.