The millions of people worldwide using gigantic coolers for the past decade, the fact that not a single motherboard manufacturer tells you not to do it, the fact that Intel/AMD/mobo makers don't void warranties using an oversized cooler and the fact that errm, no one has a problem with them all suggests you're wrong.
The "I know I'm right because I have experience" argument, which is critically flawed because most of the people on this forum have the same experience, and each and every one of them knows huge heatsinks aren't a problem. Sure, hanging 1kg off a socket A peg isn't a great idea, doing the same with any of the current mounting methods isn't a problem, the new improved mounting methods were designed exactly for the reason of bigger heatsinks.
As for a bending motherboard, lol, motherboards bend, sure, and a lot--- outside of a case, you'll find a motherboard with 4 screws correctly attached around the cpu socket will prevent almost all bending. Properly installed there is zero problem using a huge heatsink, AMD say so, Intel say so, the heatsink manufacturers say so, mobo makers all say so, millions of people say so..... but your experience trumps them all.... lol