[rant]
Regarding the last paragraph, I am a bit confused. The 4e character builder only works on windows with silverlight and is really really slow and creates character sheets that are 4pages at level 1 and quickly increase to 10+ pages. Part of the reason it's so helpful is that there are sooooooo many splatbooks for 4e. There are basically hundreds of feats - per class/race. If you want to update your character, you can't do it on your tablet, you have to start up a windows PC to do it. In addition, it costs 6$ a month to get this.
One of the players in my group used the character builder and created a character that was just ineffective. He had tried to optimize, but there are so many bad options in 4e that it's quite hard as a casual player to get anything out of it. Typically you have to select x class with y power and z1, z2 and z3 feats to be effective. I helped him out, which took something like an hour, sifting through powers and feats to find combinations that actually works well together. With hundreds of feats and powers to go through, there is nothing casual friendly about 4e.
[/rant]
It only costs one person in the group $6/month - indeed it's outright silly to not share an account, because then the DM can't look at your characters and so on!
I agree that Silverlight was a dumb choice, but "OMG FINDING A WINDOWS PC IS SOOOOO HARD!" rings very very very very false to me

Every Mac user I know who plays games of any kind has a dual-boot or Wine so you really just need to find "A PC". Yeah, not a tablet, that sucks, they need to do better. It's still good.
As for "one of my players failed to create an optimized PC once", well, dude, I don't buy it. Casual players don't create highly optimized PCs. Period. That's way of the world. So if he's really casual... if not, he should know the trap options. The builder still makes building a PC easier - if he uses the Essentials method, he also won't be bothered by scary giant feat lists and will come out with a perfectly functional PC. This isn't 3E. The difference between a normal PC and an optimized non-exploit-y one is fairly reasonable (exploit-y ones obviously can go far beyond, but it was ever thus in D&D, and most DMs go "Haha no.").
The point is, it's still vastly superior to not having it. Crazy superior. All of my players successfully created their PCs entirely without my help. That's unprecedented. One of them was new to RPGs (all were new to 4E), two others casual-as-hell. I can easily check their PCs after the fact and suggest adjustments, too.
Bolded bit is simply untrue, by the way. Not even arguable. Effective and optimized are not the same thing.