Because they're rich and powerful and its easier to belittle people with genuine concerns and with some incomplete evidence than it is to answer questions that

Because they're rich and powerful and its easier to belittle people with genuine concerns and with some incomplete evidence than it is to answer questions that might threaten their rich and powerfulness. And because there are a few who take their theories to extremes without evidence, its easy to lump all together with the crazies and demean them.