Because you don't know how to make a taxi line in Sketchup, Blender is better. You obviously didn't read the tutorial, or that question would be answered:
All this has been done with Sketchup and not a lick of it with Blender. Opinions are meaningless without context.
Oh ya, I almost forgot, thanks for reminding me. Sketchup is indeed superlative for architectural work as well. Below is a site plan I did for an employer when work was slow a few winters ago. So Sketchup can do that too. The intended impression is that one can accomplish just about every possible thing one would need to simulate using Sketchup, so the choice is indeed personal.
For me, the specific difference is the learning curve. In that regard, Sketchup is nothing less than intuitive. Additionally, it is cutting edge. People like ThomThom, Eneroth and the Sketchup team are constantly cranking out extensions and I regularly stumble across something written specifically for flight sim or train sim. To me it's exciting - and I like the open source/dev nature of Blender, it seems like they are trying to continually improve, which I really endorse. Ultimately I have a short attention span, so Sketchup got me going while I was still thinking about it.
As far as pro vs free, there is nothing about the pro version that attracts me. Any additional capabilities it offers can be surpassed (for free) with resourcefulness. Ultimately, the pro version is a conduit for legitimacy. If you make money doing 3d work, it is extremely unlikely that you developed the platform to present your work. You have to pay for the simulator, you have to pay for the computer and while you are learning Sketchup is free. If you start making money off of all that development, it is only fair you share. The same would be the case with Blender and you are fooling yourself if you think otherwise.