To be fair, he said it was rave music. Rave music only puts the drums in and out, not changes the volume (most of the time, and is part of why it grates on my fucking nerves after a few minutes). Hell, he might have WANTED it to all be the same volume. Conversely, he might not have known about the automated volume features, or was using analog (non-comp) equipment and just set-it-and-forget-it. MUCH is involved in what specific programs/instruments/devices were being used. A drum machine and a synth going in to a 4-track can still sound pretty good, but limits your options after all.
In rave/dance-hall techno, the best way to de-emphasize the drums is to just cut them out for a bar or two - the synths are percussive enough to carry the tempo. At most you probably want to fade up a snare build before coming back in with the full drum loop again. Another option is to drop out parts of the loop - for example, drop out the snare for a measure or two then reintroduce it, or even drop out some of the beats to build a section.
Also, using multiple tracks of the same drum loop is ... not a good idea. All you really need is a stereo-pair track (if you're taking a drum loop) or a half-dozen or so tracks (kick, snare [top and bottom if you want some variety in the snare sound], one each tom, and an overhead pair) if you're using something like Pro Tools or similar programs and recording a live kit. Add in a stereo-pair for an effects track (for reverb and any delays/gates/filters/compressors) and there you go.
Making copies opens up (even more) phase cancellation options, and that - as LMNO said - is very bad. It's already relatively easy to get phase cancellation when mic'ing a kit, especially in a large room or with distance mics.
And yes, I went to college for this