25-ish years after the event I'm not sure how or why I chose to collect orcs and goblins as my preferred Warhammer army, but I do kmow that when Ravening Hordes was released they were the only army that really interested me. I'm guessing that even as a fairly conformist teenager the "good guys" were a bit humdrum and, while chaos at that stage had a firm place in the Warhammer setting it didn't have the level of prominence it does now, orcs were probably the default bad guy.
Even today while I appreciate the undead army on an asthetic level the only other army amongst the "bad guys" that appeals would be skaven. No longer being a teenager though I could see myself fielding dwarf, norse or Empire armies quite happily these days.
Other than the aesthetics there are probably two criteria for selecting any wargaming army - perceived power (or convesely lack of balance) and monetary cost. As a cash-strapped teenager the latter did start to weigh on my mind after a few years of wargaming, and I wondered whether wood elf or chaos armies would be nicely effective and much cheaper to field. By that point though I had invested financially and emotionally in the orcs and goblins so that it was a bit of a moot point.
I'm in a similar position today, in that I still have most of an orcs and goblins army (albeit that most of my old goblins I gave away, and a good chunk of the orcs are new eBay aquisitions), but would quite like to field a dwarven army instead (or as well). The financial investment in either completing the orcs and goblins, or building a dwarf army, isn't trivial, but much more significant these days as someone with a family and a job is the time investment in painting and preparing them for the table.
I'm still mostly happy with the choice I made all those years ago, but I do hope as well to be able to field a smallish dwarf army, plus the skaven side from Vengence of the Lichemaster, one day. If what I've seen of the hobby recently though is anything to go by I will then find excuses to build up yet another army...