To give it some context, here are the Mars failures:

Soviet Union/Russia: 1M No.1, 1M No.2, 2MV-4 No.1, 2MV-3 No.1, 2M No.521, 2M No.522, Kosmos 419 (3MS No.170), Mars 96 (M1 No.520), Mars 1 (2MV-4 No.2), Zond 2 (3MV-4A No.2), Mars 2 lander (SA 4M No.171), Prop-M Rover rover (SA 4M No.172), Mars 4 (3MS No.52S), Mars 5 (3MS No.53S), Mars 6 (3MP No.50P), Mars 7 (3MP No.51P), Fobos 1 (1F No.101), Fobos-Grunt

US: Mariner 3, Mariner 8, Mars Observer, Mars Climate Orbiter, Mars Polar Lander, Deep Space 2

China: Yinghuo-1

UK/Europe: Beagle 2, Schiaparelli EDM lander

Japan: Nozomi (PLANET-B)

Also: Soviet Mars 3 lander (SA 4M No.172) landed, so counted as partial success, but contact lost 14.5 seconds later. And Soviet Fobos 2 (1F No.102) orbited successfully then lost communications during landing, so a partial success.

https://en.wikipedia.org/wiki/List_of_missions_to_Mars

Also it's pretty dusty, so doing a controlled burn all the way down (like SpaceX does on Earth) kicks up a huge dust cloud which settles on all your nice solar panels.

I don't think the atmosphere is the problem with landing heavy landers like we do on the moon. For some reason I think gravity is the main problem. The only effect I can think of the atmosphere would have is on engine efficiency, and it's so thin I doubt it's much of a consideration at all.

You are very wrong. Read the literature.

Yea I started thinking about it after I posted. Ya know, the heat and stuff.