This is true, but I think it's a league-wide issue. Probably partly due to competition with football and the World Series, and partly to "ramp up" the season, the league doesn't schedule a lot of games in October...not just for the Bruins, but for everyone. Right now, we don't have the fewest games played - that award goes to Minnesota and Carolina. (They'll both catch up with us, and be tied with us at the bottom, perhaps with other teams, when we resume Thursday.) We're also tied with 7 other teams. So, compared to the average NHL team, we're not HUGELY lagging....yet.
When you think about it, March is a good month for the NHL to stuff games in. The only competition is the NBA, and they're always competition except in the very first week of the season. Even March Madness only takes a few days out of the schedule, and I don't think there's a huge college basketball/hockey overlap. Plus, more games later keeps the suspense going - if teams had 4-5 day long breaks in March and early April, it would be both boring and unfair.
That said, I peeked in the schedules for the Atlantic in March, and the Habs, Lightning, and Sabres have a decent-sized break in March. None for the Wings, Panthers, Lightning. Sens have 16 in 31, so it's packed - but a lot of 2-on, 2-off.
That said, schedule making is tough. You have to balance the NHL, NBA, concerts, family shows, and regional events (The Tradition, Beanpot, Hockey East, for example) for every stadium. It could be that the Garden likes the arena packed with hockey fans in March. They do try to make sure teams play approximately the same number of games weekly/monthly and that there's not huge gaps, with the exception of the bye week.
The other thing to consider is that the season started a week early. Not sure if that was in anticipation of a possible Olympic visit, which never panned out, or if it's a change to get fewer back-to-backs in there, or to help with the bye week issues. But that should increase the average gap between games.