I have been a long time "skirmish" game player. I never really got into the large "army" sized games (save for some dabbling in micro-armor, a few games of 40k and 1 or 2 games of Warmachine).
I think the reason that skirmish games have gotten a lot of attention lately is because there are more and more high-quality skirmish games being produced. Malifaux and Pulp City are two games that come to mind. They both have well written rules and good looking minis to boot. On the horizon there are several other games due out that will continue this trend (MERCS and Bounty come to mind).
I think there is some burn-out with large army based games. Army games tend to have a power creep, making what ever the newest army (or codex) the most powerful. This encourages tournament players to spend more money, in hopes of winning the next tourney. Whereas skirmish games release new characters/ minis to encourage adding new "flavor" to your warband.
IMO, skirmish games are, and have always been, the better gaming style. You can get into a game for a low cost (usually $100, or less, gets you a rulebook and 10 or so minis) and be playing relatively quickly. After the initial investment, you only need to buy 1 or 2 minis a month, if you so choose, to continue building your army. I think this is better than dropping $600 to build a competative army... only to scopp 10 minis that you spent 50 hours painting, after the first turn.