I'll give my perspective here, as a (soon to be ex-) climate scientist (paleoclimatologist/micropaleontologist). I'm sure you'll disagree with some points I make but this is my experiences and opinion.
Here in Germany, acceptance rates for proposals are at an all-time low (circa 25%). Professor positions are all but saturated. This means that anyone wanting to go into research is going to have to spend the next 30 years working at the same pay grade as a post-doc researcher (in Germany, this works out to something like 50-60k EUR, depending on the funding source, but German taxes are high so net salaries are in the region of 30k). Well, 60k isn't a bad living at all. However, outside of academia most of these people could earn much much more. A colleague of mine quit last year and now does contract work as a biostratigrapher, and earns closer to 200k. Another former climate modeller now works as an analyst for a commodities trading firm, and probably earns 10x his former salary. So whilst researchers can earn a 'comfortable' salary, I doubt many are in it for purely monetary purposes when there are much better alternatives out there.
Added to this, is the fact that a scientific career is highly uncertain - a few rejected proposals, which is not uncommon right now, and researchers find themselves unemployed without redundancy packages. A typical grant length is 3 years, which means that once a researcher has a grant, the cycle of writing proposals begins again almost immediately, stifling the time that could be used to do research (The proposal review process itself takes about 5-6 months). The result of this is that 60-70 hour weeks are the norm, not the exception, as researchers juggle reviews, proposals and teaching with their own research interests. Most of the time researchers also have to move to different universities and countries every few years, so its not surprising that 50% of scientists in my department have no partners or children.
Now, I've made research sound like a horrible job, which its not. There are of course good things about it - you are able to work almost fully independently, you can work on something that is interesting and exciting, with the newest technology and tools. But for me, this wasn't enough - I want a stable income to support my family, and the opportunity for career progression. I'm actually leaving to join a scientific publisher, and in doing so am getting my first pay rise (by about 20k, not an insiginificant amount) for 5 years. Of course, this is all my personal anecdotal experience, but I've never seen anything to suggest that any of my colleagues are in science for the money.