What Blizzard is basing this on: They did studies on who continues and who quits the game during a fresh start. I don't remember the numbers exactly but it was a quite a big bunch that quits before level 10. If it wasn't about 20% to 30% at least.
So they see potential if they make the first-time experience more "pleasant" for new people as they have quite a lot of work to do there as many people "find it frustrating" or for whatever reason they might not want to continue to progress their character.
In any case, absolutely -- I see the other point as well, everyone's in the same boat. Tough shit. Or whatever. I prefer this one personally. But understanding what they're basing it on is a good thing even if you might not agree or like it.