Always remember that Mars is a planet far away in space and long away in time (buillions of years). We're only guessing about surface conditions and the inferences we draw from them become more and more frail as they stack.

Observation:-

There clearly are wavy laminations in the rocks of Meridiani. These have a sulphate chemistry and interesting nodules.

Inference:-

These may well be the sign of standing water and ripples

Cautinary note:-

Given the extraordinary implications of this inference, compared to the environment of modern Mars, we must be careful not to overinterpret the evidence, and also to acknowledge alternative possibilities.

One alternative:-

These could also be direct chemical precipitates at the surface, formed by seeping groundwater - i.e. no free liquid at suface other than a damp highly acid film. These sorts of environments on Earth - Sabkhas - exhibit wavy laminae, nodules, and sulphate chemistry. In short, they also are a close fit for the observations we have from Mars.

Steve Squyres ia anice fellow and reasonably smart, but he's buried in the moiddle of the NASA water-on-Mars machine so he doesn't get to hear too many alternative voices.

Nobody has a monopoly on insight and rightness. Not me, not him. Likely we're both wrong, to some degree.