The solution described is incorrect. Area charts and column charts are used to display different types of information. Area charts (and line charts, similarly) are used to display continuous data - data that must pass through point B to get from point A to point C. Column charts are used for non-continuous data.
Some examples:
You should use an area chart (or just a line chart) when tracking your weight. If you weigh yourself on Tuesday and you weigh 150 lbs, and then weigh yourself on Thursday and you weigh 155 lbs, because of how weight works, you can assume that between Tuesday and Thursday your weight traveled through all the points required to get from 150 lbs to 155 lbs.
If you're tracking the amount of hours you sleep every night, you should use a column chart. Just because you get 6 hours of sleep on Tuesday and 8 hours of sleep on Thursday doesn't mean you got 7 hours of sleep on Wednesday. The data isn't continuous.
For market share, that data is continuous - you can't get from 10% market share to 15% market share without passing through all the percentages in-between. Therefore, a column chart is very much the wrong way to display that information.
Area charts differ from line charts though in that they emphasize the cumulative integral under the line. In your weight example, in general the total of your weights on each day multiplied by the number of days is not a meaningful statistic (except perhaps to the operator of the elevator in your building who is tracking cumulative strain on the support cables). An area chart makes sense if the product of the x-axis and y-axis units make sense.
Data continuity is a secondary concern; there's no reason not to have a stepped area chart, which is the union of a set of adjacent bars representing discrete measurements. And sleep hours per day do accumulate nicely over time, so an area-emphasizing plot does make sense (sleep hours per day * days = sleep hours). It lets you look at two parts of the chart and assess 'did I get more sleep in this period or that period'.
The solution described is incorrect. Area charts and column charts are used to display different types of information. Area charts (and line charts, similarly) are used to display continuous data - data that must pass through point B to get from point A to point C. Column charts are used for non-continuous data.
Some examples:
You should use an area chart (or just a line chart) when tracking your weight. If you weigh yourself on Tuesday and you weigh 150 lbs, and then weigh yourself on Thursday and you weigh 155 lbs, because of how weight works, you can assume that between Tuesday and Thursday your weight traveled through all the points required to get from 150 lbs to 155 lbs.
If you're tracking the amount of hours you sleep every night, you should use a column chart. Just because you get 6 hours of sleep on Tuesday and 8 hours of sleep on Thursday doesn't mean you got 7 hours of sleep on Wednesday. The data isn't continuous.
For market share, that data is continuous - you can't get from 10% market share to 15% market share without passing through all the percentages in-between. Therefore, a column chart is very much the wrong way to display that information.