I think those of us on the other side of the coin think of it this way: "I enjoy building things for a reason, building just for the sake of building isn't fun." (paraphrased from a guy on the ic2 forums). I like building a rail system knowing that it solved a problem I had to overcome, like "how do I get the stuff from my quarry back to my base?" If it solves a problem, then riding that rail out to my quarry area is fulfilling to me. If I just made a rail system for the fun of it, it's not fun for me.
IMO this is why some people want balance between mods. If you have tesseracts, there is no reason to build a rail line other than to look at the cool rail system. Which as im saying, i think its not enough for people like me. IMO most people use the most powerful options in general. You saw lots of people using squid biofuel setups for no reason other than it provided you a ton of power. How many people use Ic2 miners or steves carts drills vs a BC quarry? And now i see posts on multiple forums where people say BC can be retired because of the new Ender Quarry, which is definitely better. To me BC pipes are cool to look at, but if i post a screenshot somewhere, I ALWAYS get people saying 'why are you using those? use Conduits!' Conduits are the best choice. Applied Energistics vs a pipe sorting system. AE isnt really creative at all is it? A redpower sorting machine though with a bunch of pipes is cool as hell, but in 1.4.7 youd see 1 out of 10 people choose it over an AE system. probably even less.
If you look at most packs, people often use the best items from each mod. Railcraft boilers, factorization barrels, BC quarry, Thermal Expansion ore processing. Ultimately an AE system. Look at 10 threads where people posted their bases, and until recently with some of the new mods coming in, this was what you saw about every time. Just look at my sig, KirinDave knows it. People use a mod because its easy and efficient, few people do things just for giggles.