I'm inclined to agree, but for example, let's take a look at professional bowling. If I remember correctly, (haven't kept up in several years, the format has likely changed) the tour stops start on a Wednesday and run through Sunday where the quarters, semis, and finals are televised. Wednesday through Saturday these guys may bowl up to 100 games to make it to tv. Having been to a few of these events, these guys would be dressed in shorts and tshirts while they grinded through the field. Come Sunday, they donned slacks and collared shirts with their sponsors on them.
Soooo, for pool players, I'd say it's cool to be comfortable during the early rounds but dress appropriately when the time comes