Winter is the best season for hiking
A lot of people seem to be afraid of hiking in the winter, but it's actually my favorite time of the year to get outdoors. Winter weather can make hiking a lot easier and more enjoyable, at least here in the north east.
Some of the biggest annoyances of hiking are completely absent in the winter: bugs, mud, heat, and crowds. Walking on packed snow or ice is almost always better then trudging through sharp rocks and mud (provided you have microspikes). And the cold keeps away the big crowds and biting mosquitoes you get in the summer. The body heat you generate from walking keeps you warm without overheating you, and you need to bring less water than you would in the summer.
Winter views are among the best you'll get, with snow providing contrast against dark rock and trees, and without leaves and foliage to obscure your sight lines. Frozen streams and iced-over trees also make for interesting views.
Even if the weather is bad, it's much nicer to hike in the snow than in the rain. The only real downside of winter hiking is that you have to carry more gear to keep yourself warm when you stop, but you also have to carry less water so it's a small tradeoff.
However, backpacking in the winter doesn't share all the same benefits. Sleeping in subzero temperatures requires so much extra gear that it often ends up not being worth it. In the end I think the ideal balance is to use the summer for more laid-back camping and backpacking, and use the winter and shoulder seasons for more serious hiking.