MYOG: lens cap retainer

I've been putting together a few bits of gear for various reasons. I'll probably get to saying more about them when they're better tested, but I thought I'd start with the one that I didn't even really think of as some gear: aretentioncord for the camera's lens cap. I've dropped a pretty penny on a bit of heavy camera kit and expect that I would lose the lens cap within a week as it comes, so had to do something about it. I found a cap for a Canon in Forbush, so it seems that maybe someone nearby needs a little help.

So, get hold of a bit of cord and glue. I've got some from Michael's that comes in a dozen colors plusmetallic,but went boring and grabbed black. It's thin, tough, and not at all stretchy. The glue is some E-6000 I picked up in a pinky sized tube for even less. Locate a spot on the side of the lens that is far from buttons and doesn't move and cut a bit of cord to reach from it to a spot on the cap plus an inch or so extra for slack. Dab a bit of the glue on the chosen spot on the lens and stick the cord into it, then add a bit more to cover the frayed edge. Do the same on the other end on the cap and let it all dry.

I can just pop the cap and let it hang now. The glue isn't showing any wear from the treatment over a few hikes and an overnight. I've already bumped the lens twice in ways that popped the cap off. I noticed right at the time, so presumably would not have lost the cap. It might take me another month to get to a point where I would have lost the cap were in not connected, but it really makes the cap easier to handle.

Why doesn't the lens come with the cap tied on? I must be missing something, but I haven't found any drawback yet.