The distinction I make is that roguelites are designed around metagame progression rather than / in addition to the in-game progression used by roguelikes.
For example, Rogue Legacy is almost entirely focused on metagame progression between runs, whereas your character barely develops at all mid-run. Classic rogue-lite.
The problem is that roguelike is a very old and established genre, and it is topdown RPG with permadeath. I don't see why meta progression is a feature worth of its own genre - you could easily add it to a roguelike like nethack without any change of genre.
For example, Rogue Legacy is almost entirely focused on metagame progression between runs, whereas your character barely develops at all mid-run. Classic rogue-lite.