Yes, but who is to measure what is worthwhile to the party. In a combat heavy campaign, a fighter taking summon familiar is only screwing him and his party over, but in a campaign focused around stealth and intrigue it could be one of the best feats in the game. WotC can't balance every feat for every possible occasion. And while I agree that preserving sacred cows for the purpose of tradition alone can be silly, you also have to remember that there are literally hundreds of RPG's out there, and if D&D changes too much too fast it risks losing it's identity.
Yeah. Imagine taking a level dip in rogue. You'd gain 2d6 sneak attack, a rogue scheme, skill master(both the min ten and the +3 or ability mod thing). That's insane, you'd be a fool not to take it. The implication I got is that if you start as a rogue, you get all that at once, but if you enter rogue later, it'll take a few levels until you get all those abilities.
On the other hand dipping spell casters they said will be more viable, as a higher level character might get slightly higher level spells than just level 1. Since spells don't scale with level 3 level 1 spells would be pretty useless to a level 15 character.