I think it's kind of pointless comparing someone who's doing full service on mowers to someone only sharpening blades. Someone having their mower serviced, including having the blade sharpened, has never even seen or held their blade before, and having it sharpened is just part of the complete service they're paying for. They don't even think about what it looks like and just trusts that it'll be sharpened.
Someone who removed their blade and sees what it looks like doesn't necessarily expect it to be cleaned, but I'm sure they appreciate it. It's customer service that encourages repeat business. Some car dealerships give people free car washes that buy their cars from them and/or bring their car in for service. Same thing.
There is something to be said about this thought process.
However, there are very few people that only sharpen blades.
For those people who do sharpening services they typically sharpen more edges of other items than they do mower blades.
Now I'm sure you could find someone who would be an outlier in the statistic but this is how it works out throughout the country for the most part.
Here's why:
The vast majority and I mean a very high percentage of homeowners and mower owners do not have the ability, tools or want to bother removing the blade themselves.
As we go further and further into time and when you start talking about younger people you'll even see this is more of the situation.
It's also even more prevalent with the battery powered mower owners not to mention that most of them are even harder to remove and reinstall without breaking stuff or the plastic spacer or blade adapter pieces etc.
So in generalizations let's just talk about round numbers.
For every 100 blades that get sharpened probably 90 to 95 of those are on the mower and the mower is dropped off or presented to the person doing the sharpening or servicing.
A very small percentage like this 10 or 5 or fewer or where a person removes the blade drives it to a shop and hands it to someone to get sharpened.
Lots of reasons for this but most of the ones I covered earlier.
It also is kind of time and effort prohibitive because most people can't sharpen a blade while you wait or won't and I don't blame them.... so normally you have to make a second trip or at least go have lunch or something while they sharpen your blade or blades.
So whatever the reasons and logistics, most mower owners don't take the blade off and do it that way.
For the few who do though I will agree with you some pay attention to it.
Some do not!!
It is amazing how people vary in this nature but some people will critique the edge and look at it and of course they don't necessarily know what they're looking for and this is until another discussion which I'll touch on in a minute, and other people just take them and go stick them back on and many times they put them on upside down!
Getting to my theory that people should leave their stuff alone because far too many people do more harm than good.
Now the ones that do inspect them, they're probably thinking sharper is better and we all know that technically speaking or at least for a lot of people that is not the ultimate desired blade geometry or method but try to tell them that.....
So if you're going to clean the blade nicely to make it more presentable to make it look like you spent more time, what you did, and did a better job for them for the money....then you probably should go ahead and make them razor sharp so they really feel like they're getting their money's worth. LOL
But I won't argue that point too much because there is no consensus and no guaranteed right or wrong way to sharpen a blade and it's mostly a matter of opinion and that's why they would this thread came up about let's discuss blades I said.. no please, let's not. Lol
Most people who have the sense that ability to take their own blade off aren't worried about the look of the cleanliness and if you start painting them to touch them up and they get paint on their hands or their car etc they'll probably quite irritated that you did that but somebody mentioned a quick coat of paint on blades.
Most people realize that the metal part is fairly unimportant or the part that gets dirty and that The cutting edge is what they're paying you to sharpen and I guess most of them just have to take your word for it that they're balanced if you even do that because most people don't know to ask because they don't know it's a thing.
But to sum it all up, I will say when someone brings me a blade and hands it to me to sharpen I typically do a little bit better job on it especially if it's all nicked up and dinged up to not only get all the nicks out of it but to kind of smooth it all out so it looks better and presentable and does it have a little waves in it and stuff.
This often means a little more time but it also means taking a little bit more metal off of the blade to get the shape more uniform.
I don't have her spend much more time cleaning them because the most I really ever do is run a putty knife across them to knock off any big chunks that are build up.
I still maintain that even that makes very little difference because once those chunks build up they pretty much stay there like they're welded to the blade and when you remove them they're just going to build back up again but luckily they usually build up on both sides symmetrically so it doesn't affect the balance and it's also so close to the center of the blade that it wouldn't affect the balance anyways.
It's all a lot of hoopla for no extra real benefit.