I roughly agree with that, but I'm not sure "lines of code" is a good metric for substantiveness. Sure, something which is around 10 lines is probably not substantial whatever it's doing (it's arguable you even have a copyright interest in something really trivial).
But on an ongoing basis, does it matter if the thing you've contributed is only 100 lines if it's doing something rather clever and really improves the software? Likewise, if you contribute twenty 10-line patches, are they insubstantial?
Trying to draw this line is why I think all contributors should be treated equally; otherwise it just becomes a divisive issue about trying to weigh the contribution people are making, and that's about as ungracious as you can get.