What bitcoin proposals do you regard as controversial or even harmful ? And why?
I believe that the most dangerous proposals are the ones which offer a trade-off with decentralization.
AFAIK, decentralization must be protected at all costs, and this is the one thing that makes bitcoin valuable and useful.
Anything which goes against the main ideals which make bitcoin what it is are very dangerous proposals, over the years users have proposed all kind of dangerous changes which fortunately have not occurred and we hope they never do, for example we have heard proposals about allowing to chargeback transactions with the excuse of recovering the money which is stolen by scammers, increasing the number of coins which will be mined and lately many users have proposed for bitcoin to go from POW to POS.