Well as for one I can tell you all that the TMP uniforms are a very well tailored costume! I own a actual screen used costume and for some reason folks do not like them. I have seen many costumes from trek over the years and most are cheaply made. The fabrics and tailoring in TMP uniforms are first class! As for them looking like PJs, well nothing looks more like a PJ than the first and second seasons of TNG! I love TMP and I like the uniforms in the film but I have to say it took a while back in 79 for them to grow on me!
Back in '79, they DID remind me of the Space:1999 uniforms...but that was not a bad thing to me. I was a big 1999 fan.