I think WHFRP's system is very different. For example, Chaos is not Chaotic Evil. All the Chaos Gods combine both positive and negative aspects, even if they are generally the bad guys. Chaos is much more like CN in 3.5. So although there are 5 alignments in both WHFRP and 4e, the choices between alignments are not the same. This is key.
Consider if there were 5 different alignments in 4e: LG, NG, CG, LN, CN. If you wanted to play an evil or neutral character, you'd be forced to shoehorn him into an alignment that doesn't fit him at all. Can we all agree this would be bad?
That is a severe version of the problem with 4e's alignment system: it has few choices for alignment and they are bad choices. This forces characters to be shoehorned into descriptions which do not fit them.