1) Our water is incredibly hard. Even with a softener, most tanks only last 8 to 10 years. The company I work for changes out ~10 per week, and 90% of them are of this vintage.
2) Crap is more expensive here. A quality 50 gallon, natural gas, power vented tank, would cost around $2300 PLUS TAX to have installed. Once the government gets paid, that's $2600 out of pocket.
Indeed.
We've been lucky that ours has lasted almost 15 years so far (i never realized the install date on the heater until i checked earlier this year).
Not all people rent though. You can buy water heaters for $500-$800 but as Real80s said, they typically last 5-10 years depending.
A quality one that we are looking to buy is near $2k.
FYI, there are several companies that do this kind of work/service (renting water heaters). DirectEnergy is but one.
I have a friend who is an exec in a company called Planet Energy that also does this as part of their business although i'm not sure if they are winding that down or not.