Well no. We're talking about a videogame after all, there's little that's going to be mutally exclusive by any inherent aspect of design. Just saying that the end result left me with different reasons to like both games. (Todd Howard has some... unique ideas on what a sequel is supposed to be though. There was some interview or other I remember him talking about that, a number of years back; when FO3 was still in early development.)
Unconnected to that, though - you ever been trying to sleep but you can't because you've got one thing that keeps running through your head? I'm just going to throw this out, and then maybe I can finally be done with and just go to bed:
I think a lot of people misunderstand what the "point" of a turn-based game is supposed to be. I always have trouble putting this into words, but I'll try to illustrate by way of example. Basically, the fun to be had in any game, is from the way that the game itself is played. Take Chess and Football, for example. I think those are good anologues to TB and RT play. (I think the parallels between the two are immediate upon close inspection, but to explain - both Chess and Football - American Football, specifically, are really quite similar means to the same end. Both consist of two ranks of opposing forces set a specific distance from each other. The first rank acts as obstacles for the more specialized second rank, with the goal of eventually reaching the key piece. In Chess that's the King; and in Football it's the Quarterback. There's some differences, sure - but I think the similarities are rather obvious.)
Both are games. The fun to be had in either is in the way in which they are played and the strategies that evolve from that. In Chess, that emerges as a focus on conserving your forces and making necessary sacrifices towards your overall goal (which, come to think of it, could well be applied to Football, as well.) The fun is in cleverly thinking steps ahead of your opponent, forcing them to make a disadvantageous move, and then exploiting their weaknesses (similar to Football, again, actually.) In Football, it's much the same, but through different means. The fun materializes as a focus on the individual meeting of opposing units, a steady advancement across the field, and so forth.
That's TB and RT in a nutshell. They both do the same things, but just in different ways. The fun is to be had in the very way they are played.
Another example is Puzzle Games. Back in college, a friend and I got very addicted to Kirby's Avalance (Puyo Puyo is much the same; and they're all very similar to Dr Mario when you get down to it.) We got very into it and began drawing parallels between that game and martial arts or some form of duelling. There were many anologues, really - timing, baiting, counter-attacks, parrys, etc. When Puzzle Fighter came out, it was even more pronounced. The game was very anologous to a game of Street Fighter, at it's essence. Choosing between big strong attacks or intricate combos, blocking, counter-attacks, etc. It was strategically very parallel to Street Fighter, but both were abstracts of an actual martial combat. One wasn't a natural progression of another - each were their own means to an end.
The fun to be had in playing a puzzle game was in the very way that you played that game. The way you approached it, and such.
Anyway, those are my thoughts. It really just comes down to preference. Some people like Football over Chess, or Street Fighter to Puzzle Fighter. One isn't inherently better-suited than the other, however. They are mutually exclusive means to and end - one does what the other can't. They're all abstracts of higher concepts - the appeal is the way in which they are played out. Just as Football isn't "dumbed down Chess," Football isn't a natural progression from the technical limitations of Chess.