It doesn't feel shallow to me.
Game systems are designed to work pretty darn well out of the box. It's often the splat books that can break a game system.
I think we will just have to agree to disagree here. As I have said Many times over the years
for our groups 3.5 was broken out of the box (PHB only) and only worked well when you used later supplements.
I can easily understanding a rookie DM feeling overwhelmed with the game in front of her, let alone the game in front of her plus a bunch of other stuff.
I agree, but one who had played before could just as easily choose to learn the 3-7 classes the players want to play, or restrict them to just the PHB and then still need to learn the 3-7 classes from that list.
See, this is where I think some of the disconnect lies. As a player, I bend over backwards to make things as easy as possible for a brand new DM (we have a brand new DM in our current campaign).
so do I, but again in the example given I don't think it is any easier to learn to run for a Ranger, Cleric, Druid, Wizard, Fighter then it is to learn to run for a Gunslinger, Witch, Cleric, Rogue, Fighter...
I do not try to argue for me to play a PC that the DM is uncomfortable with. I also don't say, "Well, the DM has to learn 5 PC classes anyway, it might as well be 3 from the core book and 2 from these other books". Who knows what other additional rules and baggage comes along with a PC class out of a splat book?
if he was going to play core only homebrew, maybe... but running a pathfinder AP is pretty easy, they go out of there way to make it so the DM only needs the basics and the AP... the players can totally make it easy with any race/class that AP supports. In some cases using the class/race that fits the AP is better and easier then Core only...
Sorry, this will be one more area where you and I disagree (big surprise

). Players should be helping new DMs, not hindering them. JMO.
the problem is in the example NOTHING shows the player was hindering or helping, just wanting to play a character.