Couple of things:
1) Having done low sec industry I'll agree that reward is absolutely not worth the risk at the moment. However, to fix that by addressing rewards only would take such a massive boost to low-sec rewards as to make null-sec comparatively worthless, because the main problem is that at the moment the risk in low is total for industrialists. It's not a question of if you get your POS/POCOs/miners/haulers hotdropped by bored null-seccers, it's when. Improved access to production and research lines in low and higher prices for sold goods is off-set by significantly smaller market share; the improved profit margin is not sufficient to off-set the necessity of replacing assets extremely regularly. Similarly for mission-runners: the risk-reward calculation there is 'how much can I make with these missions before I have to replace my ship' and to make low-sec an intelligent choice there mission rewards in low would have to be boosted out the ying-yang. And before anyone says 'Just grow your corp/join a bigger corp and take the pirates/null-seccers on', I've seen it tried and I've seen those who tried it prioritized for kerbstomping.
2)Similarly, nerfing high sec will not in any way move players into low. It may move players, or at least accounts, out of Eve all together, especially mission/mining/industrial alts, but as long as low-sec operations are guaranteed to run at a loss, it won't move them there.
3) I absolutely agree that null-sec income needs to be bottom-up rather than top-down and active player based rather than passive alliance based.
4) When talking about distribution of players in different types of space, the question of social organisation also needs to be considered. Unlike PvE games with scalable content for different sizes of groups, the most significant scaling of content in Eve is created by other players. All other things being equal, your group needs to be of a certain size to take on other groups of a certain size. (I'm leaving out the mitigating factors of player skill and strategy here as they apply in limited cases). Belonging to a corp/alliance with sufficient 'muscle' is a prerequisite for accessing a lot of low and null content (apart from the 'oh look new clone' content) however, players don't make decisions about social grouping solely (or even largely) based on content access. Many people in smaller (sub 200) corps are there not because they can't get into a bigger corp but because they are playing eve with people they like, and adapt their playstyle to the content available to the size of group they are in. Those groups are never going to be able to just 'go to null and claim sov', nor are they going to be able to successfully and repeatedly defend low-sec assets and operations against groups that have as many cap pilots as they have pilots of any type. If CCP really wants to get more players leaving high and operating largely or exclusively in low and null, they need to find ways to make that content accessible to smaller groups: and since the barriers to that content are provided by other players, not by code, that's not going to be an easy task.
5) Whatever they do, I'll adapt, although if they nerf high sec mining and PI to any significant degree I'll definitely let accounts used for those purposes drop.