But as the charts show, assistant and associate profs are in the high 40s to low 50s range. Only a fraction (a third to a half?) of all profs are full profs, and what the chart doesn't show is that the salary at promotion to full is well below the $80K range in the chart (it takes years after promotion to make to that level). That is, you might be in the mid 50s just before promotion to full, and end up in the low 60s just after promotion to full. (I just got promoted to full, and I get about 60K not counting any summer teaching. If I teach the allowed two summer courses, that would up my salary to about 70K.)
Salaries by the way vary substantially by type of institution. It's lower at undergraduate-only schools and it's lower in fly-over land (e.g. the Ohio River valley, which is where I am).
One thing to bear in mind: it is often difficult to become a college prof, and it can be tough to get tenure too. This is a real cost of an academic career, to be balanced against salaries and tenure: People are often in their early 30s upon clearing a PhD, and they often have to go through one or more postdocs before landing a tenure-track position. Mid 30s or older. Then add 7 years to get tenure. So you're an assistant prof in your late 30s or early 40s. A software engineer may well have been programming (at 60K+ a year) for 15 or 20 years by that point in time. An academic career can actually be a massive opportunity cost.