Clearly, some people are not satisfied with familiars. The OP on the thread doesnt like them because he thinks they are somehow too...weak? I'm sorry, but this is bullshit.
In 3rd Edition, familiars had half as many hit points as the master did, rounded down. A level 1 wizard probably had 4 hit points, meaning that the familiar had all of 2. If it was a toad, it then got 3 since they granted the Toughness feat (+3 hit points, flat rate). On average, its going to go down on the first hit, even on extremely low damage roll: your average goblin has a 66% chance of taking it out on any given hit, assuming it even wants to bother. I mean lets be honest: why would anyone want to attack your familiar? Its not like its doing anything except standing in as Skill Focus or Toughness.
Thats all well and good for single-target attacks, but lets take into account area-effect attacks. Familiars do not by default have any way of avoiding an attack, and while they have improved evasion, it will be harder and harder for them to successefully avoid area attacks as the party increases in level since their saves are based on the master (and wizards have shit for Reflex). If the monster has some kind of aura effect that just deals flat damage, then the familiar is screwed.
And for what? What does a familiar actually do? Not much.
You can share your spells with your familiar, so mage armor and shield can benefit the both of you with one casting. You can have your familiar deliver a touch spell, and while this might be handy in some cases its probably not a very intelligent move to try (especially if the monster has reach and/or can see it coming). Umm...it can speak with animals of its own type, and eventually can even speak to you.
You cant even argue that a familiar can be used as a role-playing foil since it cannot even talk to you until about midway through your career. Its also not very intelligent until that point, so its not like you can engage in conversations about the nuances of arcane theory or anything more complicated than eating or taking a dump.
Familiars in 4E each provide useful benefits for your character. Much of the time they grant bonuses to skills, or perhaps damage resistances. Sometimes they give you bonus languages. The point is that one feat gives you benefits that can add up beyond a feat. This isnt even counting the bonuses gained from active mode, which are certainly worth more than that. The caveat is that active mode carries risks, but not the kind that basically make you waste a feat for a year or so.
The fact that familiars do not permanently die has lead to the bizarre conclusion that these are World of WarCraft pets (because apparently association with WoW is a hell-worthy sin). First of all, if you want to argue about familiars being WoW pets you should be complaining about the beastmaster ranger class feature, especially given that you even have to use your own actions to command the thing (although to be fair you could set pet behaviors in WoW).
I frankly do not understand why some people see a mechanic, and clamor that it sucks because this-or-that game already did it. Part of good game design is playing other games and discovering what makes them work. If you see a good design element, why not use it for your own game? Halo had their own regenerating shield gimmick that was later cribbed for Resistance and Uncharted to great effect.
However...familiars are nothing like WoW pets, they just operate in a different manner than what you're used to. First of all, they arent magically enhanced animals, but arcane energy given shape. Who are you to say how magic operates in a fantasy world? Why cant wizards have functionally useful magical companions that they can reshape given a sufficient amount of breathing room? Because its "not how it used to work", or "because I dont like it"? If you want people to burn a feat that they will randomly lose access to for however long you feel like, then houserule it. Make them have to wait a year, or 1001 days, or whatever floats your boat, to get it back.
There's no reason why you cant use familiars now and not have them fulfill the same function as they did before, except that now they're smart enough to actually interact with you instead of playing the part of Lassy and forcing to figure out what the fuck they want.
Its a fucking game, and the designers want us to have fun with it. Its not fun to have your class feature killed off by accident, take a XP dive, and then have to wait around for a year or so before you can get it back. I'm glad they changed them. I want to use them, and I feel that its worth the feat. If anything I feel sorry for beastmaster rangers because they cant just pull another beast companion out of their ass if they lose one in the middle of combat.
What it all boils down to is that they're still companions in every sense, they're just useful companions. They can actually help you out and can provide entertaiment, especially if you give one a personality and play out some of the many recommended quirks. Sorry, there's no possible way I can agree with either stance.