Most retailers tend to glamorize higher thread counts in sheets. You would however be surprised to learn that most hotels prefer a 250-400 thread count range for their sheets. This is primarily because associating a higher thread count with better quality sheets is, for the most part, simply a gimmick.
Sheets with a moderate thread count are more durable, affordable, and comfortable than those with a higher thread count. To achieve a thread count in the 600-800 range, most manufacturers use thinner strands that result in weaker weaves and less durable bed sheets.
As long as the bed sheet material is of high quality with stronger fabric strands, a good thread count works better and is therefore preferred by most hotels.