Because you do not understand what GPS clocks are telling you. If I move two perfectly synchronized clocks to a distance that it takes light 2 minutes to reach it, and send out a pulse at 12 pm, then when the pulse reaches the other clock it should read 12:02. The pulse is sent back and I receive it at 12:04. Since light is always c I subtract 4 minutes and I verify the other clock was set to 12 pm at the exact time as mine. No discrepancies, everything is fine in wonderland.
But in reality when I subtract the time of light propagation of 4 minutes I find the clocks did not both read 12 pm at the same time. You then want me to believe that it has nothing to do with the rate the clocks tick. Delude yourself all you want, the clocks tick at different rates, proven since the first satellite was launched. You want me to believe that magically 4 minutes isn't 4 minutes, that the clocks tick the same but subtraction of light delay propagation gives incorrect results, yet I am to accept that anyways as meaning the clocks tick the same. 2 + 2 = 4. 4 - 4 = 0, yet clocks show they are not synchronized with the subtraction of light propagation delays. Do you really want to continue to believe all clocks tick the same, when the very data shows otherwise?
I know you don't agree with Einstein, and neither do I, but the reason he is wrong, as well as you, is it is because the clocks do not tick the same because their energy input is different. The reason why nearness to a gravity source affects them as well as velocity is that more atoms = more energy, they are pushed to larger orbits (greater elapsed time between orbit points, less vibration, emitted waves are longer).
Likewise more velocity = more energy = they are pushed to larger orbits (greater elapsed time between orbit points, less vibration, emitted waves are longer). The end output, clocks slow closer to more atoms and also under velocity (not only acceleration, but velocity). And that is why no matter your velocity light always travels at c. It does not speed up or slow down, your clock speeds up and slows down as does every single atom sharing that reference frame. Because atoms are governed by the EM force, not gravitationally. Although not technically correct since gravity is nothing more than a misunderstood aspect of the EM force. There is no mystery of a magical c except for those wanting all clocks to tick the same regardless of distance or velocity in relation to another. As if two atoms together are expected to behave the same as two separated by distance. Next you'll be telling me the electrons in carbon molecules vibrate the same as the ones in diamonds, umm aren't diamonds carbon molecules?
The only thing I am unsure about is if they are pushed to larger orbits which makes the wavelength longer by the orbital distance, or if they are confined to tighter orbits and can absorb more energy before emitting the excess before they would break free. The problem is if the current is not steady the emitting radiation would be emitted at different points in the orbit, making the detection of the electrons obit near impossible due to its vibrational and distance of orbit variation. Hmmm, can't seem to pin that rascal down can we.
Variable clocks is the only solution, and one day you will come to that realization, that there is no paradox, just two different times.
I am not the one that thinks light travels at c away from a stationary object and at c away from one traveling at 1/2 of c, yet is somehow still magically constant. I realize the clock has changed on the one traveling at 1/2 of c, which is why it still reads a velocity of c for light. But in reality the stationary object isn't, so it's clock is a variable too, not a constant. Light is not c and also c + 1/2c for two different observers, the clock has changed with its increase in velocity. [link to www.thunderbolts.info