I completely agree with you. But the question is are they able to advance far enough and cross the Rhine ?
And are they able to stay there afterwards (resist the german counter-attack)?
From that point of view stopping at the Rhine on good defensive positions may be a valid option. A bird in the hands is worth two in the bush.
But if the circonstances look good, yes take more land, industry and resources is warranted.
Thats the problem, if Germany could cross the Rhine, say in the Region of Mainz and cut off the French and UK Army, then France would be in real trouble.
The french Army doctrine, allowed no fast breakthrough movements, they had moved in a steady crawl (walking pace) to the Rhine, ever under the cover of the french Artillery. So the Wehrmacht had a big time window to respond to the attack.