I'd think insiders selling some existing shares to raise money to exercise granted options should be put too much pressure,

Often the insiders of companies do not like to gamble on the stock market. An insider excercising options and selling them is not necessarily a bad thing. Nobody should put all of their eggs in one basket and that goes likewise to directors and managers of public companies. Most of them probably have wives and families , and I am sure the misses would have a thing to say about speculating in the stock market.