I think the compromise suggested is fair. I've seen some items in-game that it makes perfect sense for them to be unmodifiable in any way. One example that comes to mind, though admittedly the name escapes me, is an armor one of my characters once found made entirely of raven feathers. An item like that would be virtually impossible to modify, dying it would probably not work properly and look ridiculous. Though, come to think of it, I'd just assumed that and never even tried to change it around at all, but it was a good example for this. I've read the entire topic from beginning to end, considered each point carefully. The suggested compromise doesn't limit you in customizing your character, just think of it from a realistic point of view. Yes, presumably any item could be custom-made to any appearance you want, however, I don't think that it should necessarily be modifiable afterward. The magic imbued into the cloth might depend on the entire piece of fabric staying the same, in other words, start trimming off pieces here and there and you ruin the enchantment.
What you die-hard customizers should have been pleading the dev team for instead is an NPC with a mannequin that allows you to select an appearance for your clothing before you buy it. The item is then unmodifiable after purchase. Everyone's happy. Just a thought. Otherwise, if you really want to get that item specially made to your liking, why not try to make RP out of it and see if a DM would possess a tailor NPC, perhaps send you out to find required materials and then makes the item for a large sum of gold (there is an item-request thread, after all). Just thought I'd suggest a few alternatives here. Otherwise, you basically have a choice. If the limited modifications that they proposed aren't good enough for you, then don't wear the item and get yourself something you can modify to your heart's content. Simple as that. That falls in line with realism as well. I've seen people wear HORRENDOUS-looking coats or other pieces of clothing in real life and when I asked why they would, their answer was "because it's the warmest coat I've ever come across" or some similar answer. It boils to your PC's ego regarding fashion vs. how badly they need the benefits of the item itself. If you were going to freeze to death, you'd wear an ugly coat if it was all you had to keep you warm.