If you have an engine failure it is far, far better to be too high than too low. It may not be that obvious that in fact you are not really high at all particularly if there is a wind gradient. This summer I was on approach to the runway in the club glider (PW5) and was sure I was way high without really watching for a definite overshoot (i.e. touch down point moving down in the windshield/canopy). In this case it turned out that after the application of spoiler when I actually started paying attention the touchdown point was going up fast
I ended up fully closing the spoilers to regain the correct approach path. This is essentially equivalent to going to full power on final in a powered airplane....not good.
The bottom line is if you are too high you go off the end of the runway or hit something at a relatively low speed. If you are too low you will probably hit something not on the ground and at flying speed greatly increasing you risk of serious injury or death
That being said I encourage all my students to mix things up after they got their license. Traffic permitting try a gliding approach high and close in. Try a long straight in starting the final approach path at cruise speed and slowing down progressively on final, and yes practice slipping, not only could it help you if things go badly but it will improve your crosswind landings.