this map is about investment, in portugal investment goes mostly to the capital where it can be redirected to the "right people" with best efficency.
the map is about the plans for each region, as expected the central government doesn't want money outside their strategic points.
Porto's administration is considerably more careful with their spending (specially during Rui Rio's tenure) and as such undesirable target for investment, besides we got to keep lisboa's debts in check.
It goes more to Lisbon because it's the largest urban area of the country.
What we should be discussing here is why isn't more money being invested in Porto, this is unacceptable 2bh.