I do understand your point, but there are a couple of reasons why we can't make every move as flashy and amazing.
Firstly, flashy moves that go across the screen take longer to animate and drag out the process (which has already been going on for years) even further.
Secondly, in order to make movement smooth, we would need to be adding an extra 1-2 seconds to each animation and we've already received some complaints about our animations causing the game to go too slowly, so if we did it for hundreds of moves, the game's pace would be even slower.
Finally, we also try to think of a move's power and rarity when animating it. We want to create a clear visual difference between things that are used really regularly that are relatively low power, and things that should be inflicting a lot of damage. This doesn't always correlate with movement across the screen, as for moves like flame charge, it just seemed like the right idea to have it go across as the concept in my head relied on that.
Overall, I do really understand your desire for more movement, and in an ideal world we probably would be able to have it, but I wouldn't get your hopes up, as the animations project has already been going on for several years, and going through the add movement to every contact move would bloat this process even further.