Possibly what he's thinking of is that it will be harder for your L16 characters to loot a bunch of rare items to send to any new alts you might create, causing those characters to be much more relatively powerful than similarly-leveled characters of newer players.
Of course, that was the objective: overpowered lowbie alts is not an appropriate reward for a high-level character. If the game designers really decide that a player has earned a reward of easily skipping through the low and middle levels, then he should just allow her to start new characters at level 5-9.