Actually, the jump suits used in Enterprise seemed to be a lot more comfortable and functional. I know Gene said no pockets or zippers, but pockets are one of the greatest advancement in clothing. Zippers I can see as being out dated since by then they could have some type of space Velcro that allows a seamless look to the uniforms.
It's conceivable that they still used zippers in the 22nd century. Gene Roddenberry was referring to the 23rd century and beyond when he made those rules. Enterprise
was deliberately a more primitive show that showed more of a transitional phase between our society and TOS.
This is evident from the fact that people still wear neckties.