WTA is not fine. Many players can win slams now but that's not because they're all that good IMO but because they're all pretty weak. If Henin, Clijsters and Williams sisters would still play at their best now, players like Kvitova, Sharapova, Radwanska, Na Li or Kerber wouldn't win titles
I mean yes in the ATP there are only 4 players who can win slams now but that's because they're too good for the rest of the field. Tsonga, Delpo, Ferrer, Berdych all could win slams if Federer,Djokovic,Nadal and Murray wouldn't play
Henin retired, Cjisters is near retirement and so is one of the Williams sisters. Bringing them into the discussion is totally pointless. Serena is the equivalent of Federer on the Women's tour so her destroying the opposition when in form is not a comment on the tour quality as a whole.
I love how Tsonga and Delpo cannot win a masters series, let alone a slam when the top 3 are around and still get hyped to the skies while Kvitova and all actually win something and still don't get recognized.
The WTA might not be at its highest quality ever but they have stabilized a lot over the past year or so and the trend is generally positive.