In any given group, about 1/3rd of my players will have some points invested in cross class skills. Balance, spot, and listen are all particularly attractive choices because no one else can do them for you, and just a few ranks can have large dividends.
Those skills along with hide, move silent, and swim. As DM, I encourage my players to diversify skills and use some of their x4 at first level. I also encourage them to diversify after play begins.
Then again, if they do, I will take the DMG advice and take into account their skill ranks when assigning many of the DCs (however, the world still exists and some things will be harder or easier).
On the flipside, if they don't diversify, I will assume they want their characters to be weak in specific areas and hit them in those areas- to encourage some diversification (just like happens in some movies and books in which the character encounters such a situation and then develops some skill).
Not everyone that disagrees with you considers themselves a beginner.
Agreed.