I disagree for two reasons:
Having said the above, I'm not a part author, nor do I create LDraw models, so I don't think my opinion should carry much weight with respect to whether or not this is a good idea.
- Stickers, being a separate object that has to be applied, really is different from a pattern. The only way to support patterns in LDraw is to have separate "patterned parts". If patterns had always been implemented in LDraw as textures, then that wouldn't be the case, since an arbitrary pattern texture can be applied to any arbitrary part, but it is the case.
- In LEGO instructions, stickers are added after the fact at arbitrary times.
Having said the above, I'm not a part author, nor do I create LDraw models, so I don't think my opinion should carry much weight with respect to whether or not this is a good idea.