Re: Why are players playing so many tournaments?
I don't think anyone has mentioned this, but there are hundreds of girls playing tennis with "top 100" talent. When you can get your ranking high enough, you enter any WTA tournament. It's a no brainer-- guaranteed income. If you think of it as gambling, you have to play as many tournaments as possible before they start to break your way. A draw could open up, and you have to be very opportunistic. Practicing at home gets you nowhere when some LL makes the final of an event you passed up on. There are more tournaments now and more competition. Travel is easier, and there's no divisor system.
Most of the girls we're talking (most every girl on tour, actually) about are losing 1st or 2nd round every week with some exception. The girls are also fitter-- they train harder.