Not typical of the Martian surface. It is considerably larger than the land area of the Earth. Landforms are at least as diverse than those of the Earth, possibly more so due to reduced gravity and erosion.
They chose a flat boring area to land in for obvious operational reasons.
Your post is proof of the author's bias...or stupidity.
I say..."Make it so."
The vast majority of the surface of Mars (95%) is out of bounds for landing with a craft like Spirit and Opportunity due to unacceptable engineering risks. Acceptable landing zones must be; 1) located in a narrow band at the equator of Mars where solar radiation is sufficient to power the rover, and 2) in lower altitudes of the equatorial band where the parachute has sufficient time to work in the descent phase. Even given these restrictions, there are safer places to land on Mars than Gustav crater. For example, Meridiani Planum where Opportunity will land on Jan 24th is considered a safer landing. Treacherous surface winds known to exist at Gustav crater posed special risks in the descent and landing phase for Spirit. Additional engineering safeguards were added to insure acceptable risk for a landing there.
The MER science team was very keen on landing at Gustav crater because it holds great potential to provide physical evidence of liquid water on the surface of Mars at some time in the past. Gustav crater is located at one end of a long, winding canyon that appears to have been carved out by water on Mars.