I did mention before that they are looking at making specific changes to some of the classes for multi class characters, to avoid characters gaining to significant of a boost from class dipping. They said it's like the version of the class for single class characters and the version for multiclass will have some differences. They want a single class character to feel powerful and complete from level one, but they don't want someone to say, gain all those rogue abilities at level one. They also don't someone who dips a level of wizard at late levels do get a couple of non scaling level 1 spells.
Read Robin's Laws for Good Gamemastering. Specialties are not just about new players, they are about attracting different types of players. There are two kinds of players D&D has never been good for, Casual Gamers and Storytellers. A casual gamer mostly wants to hang out with friends, and as a rule they hate making tough choices, and it's terribly GMing to force tough choices on them. By allowing them to make one broad choice instead of dozens of specific choices, you've made the game better for them.
Storytellers care very little for the game mechanics, they just want to be part of a good story. To them, game mechanics are, at best, a necessary evil. A system which allows them to build story elements into their character, and have game mechanics provided to them could go a long way to making D&D more attractive to them.
You have to remember that not everyone sees the core engagement of RPGs to be building characters. D&D isn't niche or cult anymore, they have to try to appeal to more than just hardcore gamers and tacticians. Considering I like to share my hobby, I'm all for this.
Unfortunately, I don't think reality will ever match up to the fantasy you desire. The fact is, some feats will always be better for some characters. A feat that helps you in melee is inherently worse for a wizard than a fighter as a wizard, due to low AC and HP, tends to avoid melee as a rule. Not to say you can't make a melee wizard, but a fighter will always find more use for said feat. Similarly, feats that give spells or enhance magical abilities will always be more useful to classes that are good at magic.
If a fighter takes arcane dabbler, they gain a couple cantrips that give them cool abilities and make them more versatile as a character, but it doesn't really increase their offensive or defensive ability in a fight. The feats in the Defender Specialty will be better at making the fighter a better front line combatant, but arcane feats will make the character more versatile over all. Sometimes you'll have to give up pure effectiveness and power for versatility, and different classes will get different exchange rates for different feats. Saying every feat should be equal for everyone is like saying every magic item should be equally useful to everyone, or everyone's abilities should work the same. They tried to do stuff like that for 4e.