Necessary? I think so. Happily, life doesn't limit us to necessity.
Available? Yes, and for good reason. I'm mowing 9 acres or so. It's not your typical flat, landscaped yard... it's rolling fields. I need enough horsepower to cut through tall grass, while driving up hill, and I'd very much like to avoid spending every daylight hour of my weekends mowing grass, so doing so at a fairly high rate of speed is desirable. The ground is rough... I'm hoping that the suspension system keeps me from feeling like I've been trying to break a horse every time I mow, not to mention easing the pounding that the mower takes.
The mower in question is a commercial model, normally sold to people who own a lawn care business. It's designed to be able to withstand duty cycles far in excess of the needs of most home owners. My old 54" Craftsman lawn tractor, for instance... I had that mower for 10 years, mowing 3/4 of an acre every week during the season. It had 480 hours on it when I traded it off. A busy mowing crew can exceed 500 hours on a mower EVERY MONTH! The hour worth of mowing I did last night would have reduced my old craftsman to a pile of broken parts. It was simply never intended to run through high grass over rough ground at full speed for hours at a time.
Reminds me of a joke I once heard... Guy was talking about his fancy sports car, how he keeps his 80 thousand dollar toy in the garage, never drives it when it's raining, etc. Country boy looks at him and says, yeah, I know... we've got a half million dollar combine, only drive it a few weeks a year :)
