You make an excellent point.
I have argued that in the years to come, the Roe decision will be viewed as one of the worst, if not the single worst, decision ever delivered by the US Supreme Court.
It was the one just before Roe, Eisenstadt v. Baird, 405 U.S. 438 (1972), which set the precedent that outlawed "discrimination between the married and the unmarried" with respect to access to birth control. Led by Thurgood Marshall's influence, the Supremes consciously used that decision to grease the skids for Roe.
In effect, the decision opened the floodgates for unmarried sexual behavior, and was cited in hundreds of lower court decisions to undo the social ethos of marriage as the only completely legitimate place for sexual activity.
Another unintended consequence of those two decisions was the "establishment" of a powerful abortion industry. Without Eisenstadt's liberalization of unmarried sexual behavior, a demand for abortion would have remained; but it would have remained much smaller, and could have been met by secular hospitals instead of having had the effect of creating profit-centered abortion mills such as Gosnell's.