There is absolutely no reason what so ever to explain why mass should be inherently attracted to all other mass in the universe.
Sure there is. Of course the most obvious thing is the mass of ourselves and anything around us seemingly being attracted to the mass of the earth.
Also, the apparent movement of the sun, moon and other planets, and, in recent times, satellites.
The problem that TheTruthIsThere is asking is WHY mass attracts other mass...it's true that RE physics doesn't know the reason for it - but that's not a reason to reject that theory.
After all - FE physics can't explain WHY the earth is accelerating upwards - or WHY the planets, sun, moon and "shadow object" do the complicated dance that they are claimed to do. FET is no better at answering these "WHY?" questions than RET is able to explain why two masses attract each other.
The difference is that in RET, one single theory of gravity explains HOW the motion of all of the stars, moon, planets, meteors and comets happens - as well as explaining the shapes of those things, how they formed in the first place - and why there are eclipses and why there are a phases of the moon. ALL of those things can be explained by one single, simple equation: F=G x m1 x m2 / ( r x r ). All of those complicated explanations in FET (or non-explanations)...are all neatly solved with one very simple equation and one very simple (albeit unexplained) fact.
The ability to predict things is the most beautiful thing about RET physics. We see from the theory of gravitation that there ought to be black holes - we can calculate what happens if two black holes might collide and how insanely powerful the gravitational wave would be - and how long it would take to reach Earth. We can build a an actual machine that detects gravitational waves...and the results it produces are a perfect and beautiful match for what we predicted...then we can build a second one and figure out where these black holes are.
All of that comes from that one single equation...it's a thing of beauty.