Personal skins should have never been allowed mods-off in the first place. It's all "me me me me me…" We lost that battle a long time ago. I would have preferred a system of personalization in which we could have added logos/markings to "unmarked" historical or fictional skins rather than creating a completely different skin for each personalized aircraft.
I once thought that would be a good idea too - some simple method of allowing personalization without having to learn to skin or persuade a skinner to help out. However, that was before the explosion in popularity of personal/fictional skins. That sort of system might work OK with a relatively small number of personal skins, but to date there have been more than 1,700 fictional skins approved for inclusion in the 7 skin pack volumes released so far, and we're likely to top the 2,000 mark with the release of Volume 8. There's only so much personalization you can accomplish with the kind of simple logo-based system such as described above.
I think it would still be nice for someone to offer to create such simple skins for players without the time/experience to create their own, but of course that would be more likely to increase the number of personal skins compared to what we're seeing now.
An unfortunate consequence of making personal skins for the exclusive use of a particular pilot might be a further proliferation of personal skins as those who had been satisfied with using someone else's skin decided to get their own. I say unfortunate because each skin is over 5 MB and so they quickly add up to a large amount of data to be stored and imported into multi-player missions.
A single pilot with skins for his ten favorite planes is taking up over 50 MB of space on your hard drive. Just imagine if everyone who has flown on Hellequins (well over 2000 pilots) had 10 personal skins approved. That would be over 100 GB right there!
Because this system is so space-hungry we shouldn't encourage even more people to make personal skins! Support skin recycling! (Or agitate for a more efficient personalization system).
As far as I'm aware, although there has been some speculation, there does not seem to be any hard evidence that the increasing number of skins is having any detrimental effect on game performance, or that the RoF engine cannot handle the number of skins currently approved for inclusion in the game. However, I have no idea if there is any sort of theoretical limit or if there will come a point where the game will start choking on all these skins. I trust that the devs are keeping an eye on this, and if such a limit does seem to be approaching I would imagine that we may see some alterations to the way skins are handled in RoF.
In the meantime, of course, if people are concerned about the storage space being taken up by all these skins, or about some theoretical/potential impact on game performance of having all these skins installed in their game, they should start using Laser's awesome (beta) Skin Manager - in combination with JSGME, this tool gives you a great deal of control over what skins you do or don't have installed in your game at any given time, and allows you to easily maintain a trimmed down installation if that's what you want to do. The Skin Manager tool, and explanations of how it works and how to use it with JSGME, can be found here: Beta Skin Manager for Rise of Flight (beta03)