This is the equivalent of a guy pointing out that he is smart, tall, reasonably good-looking and successful in his job, but struggles to attract girls - then asking if it is because his muscles are too big. I mean, after all, maybe that's what is keeping the girls at bay, right?
If you are a rocket scientist, there is a chance that your academic prowess might be intimidating to an average guy, in the same way that a steroid-injected meat-head's muscles might be a a little much for the average girl. Yeah, sure, there is a risk that pouring too much of your energy into academics will turn guys off a bit, especially if it is done as a mask for your feelings of inadequacy with respect to other women. It's the same risk that a guy runs when he devotes the majority of his free time to getting jacked, especially when it is done as a mask for his feelings of inadequacy relative to other men. But the muscles themselves aren't the chief problem, and neither is your degree or your job.
It's way more likely the case that you are underestimating the importance of your weight, or that you cut your hair way too short, that your posture is horrible, that you talk like you want men to believe you're stupid, or that you don't realize how much your lack of boundaries is making men dismiss you. These are the kinds of things that actually turn men off, in the same way that low self-esteem and low intelligence are the kinds of things that actually turn women off (not coincidentally, these are common problems among meatheads).
The women who ask this question are always asking "why don't I get any attention from the men I want?" Their question is never "why do I get tons of sexual attention from men, but none stick around?" (some do ask this question, but they never then go on to blame it on their degree or job). If a woman were asking the latter question, I still wouldn't jump to the immediate conclusion that her degree or salary was the problem; I would look first to her personality. But if a girl isn't even getting sexual attention from the guys she is concerned about intimidating, I guarantee her hypothesis about her threatening intelligence is wrong. Why? Because there is a remote possibility that men will be intimidated or turned off by a woman's brains or job when they are considering her as a girlfriend or spouse, but there is no possibility that it will prevent at least some guys from trying to get in her pants. None whatsoever. Men go for the girls they are physically attracted to, then choose from those the ones they are personally attracted to. Only after that do they take into account things like brains and (much later) salary or professional success. You can't blame academic or financial intimidation on your inability to get a boyfriend or husband if you aren't at least getting sexual attention from the men you want; it'd be like blaming the power outage in your house on a government conspiracy or that neighbor you hate... during a raging thunder and lightening storm.
No, in all likelihood, your academic degree or high-paid position isn't the fundamental problem; but it is an very convenient scapegoat - and an ego-boosting one at that. It is a hell of a lot easier and more satisfying to blame big muscles or advanced degrees for your lack of success with the opposite sex than it is to find out (or admit) what's really wrong. And for women, what is really wrong almost always has something to do with your looks or personality, which, thankfully, are both very much controllable.
1. Men Don't Care About Your Accomplishments
2. The Importance of Personal Boundaries
3. Human Energy is Conserved
4. Are You Repressing Your Femininity?
5. What Men Think About Your Intelligence