I don't think a ground war in Syria is 'the reality of the situation' at all. It would be a huge gamble, which could have terrible consequences, for example, large numbers of civilian deaths, the radicalization of people across the Middle East, the growth of extremist groups. It would be a gift for the recruiters of IS and Al Quaeda - the crusaders are here.
It also requires a plan, the thing that was lacking in Iraq. OK, Western troops could take IS-controlled towns easily, but what then? The jihadists would presumably melt away in classic guerrilla fashion. What do Western troops do then, pursue every rebel group in Syria? What would the cost be - in trillions?