ITs your business only you need to please yourself. Stick with it.There is enough boring work in each day its a little big of joy to look forward to.
I'm inclined to agree with this.
There are many different types of people in this world all motivated by different things.
Some are motivated by money where others are motivated by doing a good job. Most high achiever sales people are motivated by money which isn't always a good thing from the customer's or employer's point of view. On the other hand there is a dying breed of tradesmen out there that take pride in their work. And then there is another lot that don't give a damn and do as little as they possibly can get away with - work being the finance needed for the next party.
As per Slap, when you are suffering with your health then you are inclined to see things differently. You start to appreciate that you are mortal so take time along the way to pause and enjoy your surroundings. For us older ones, it also a time to catch our breath.

I have always believed that cleaning windows is a give and take thing. You can have two 'identical' semis together with the same UPVC windows, yet one will always seem to take longer than the other, yet you have priced them the same. The one giveth and the other taketh away in my books.
I have a number of houses which I do which just cover our costs. We are also aware of some old ones who genuinely can't afford to pay large sums for window cleaning, so these are below our usual pricing structure. Somewhere along the line we hope that we are doing a tiny bit to help those less fortunate. But overall, we are paying the bills just. I'm happy about that.
The problem is when you start to begrudge doing the job. When that extra 15 minutes of extra time means more than other things, such as the view, the piece and quite, the lovely cup of coffee and piece of cake after, etc. Then maybe its time to call quits on the job. It doesn't mean that you have a wrong attitude at all - as Slap says its up to you and how you feel about that job.
Doing a job right on the sea front can be very soul destroying as salt spray makes the windows greasy and if using WFP can cause streaks. I know from experience as we clean a couple of sea front homes on the North East coast.
I recently commented on a thread about a windie cleaning a McDonalds I was in. I felt for the windie as those just cleaned doors where already filthy before he had finished the next couple of windows. I could see that this windie really took pride in his work, so for him, doing a 'perfect' job was his motivator. But I could see that he did the best that he could, even cleaning the 'offending' doors a second time as he left.