Arguably the most important mitzva of the holiday season, and one which can be incredibly difficult for many people to actualize is the mitzva to be happy: “Vesamahta behagekha” (Devarim 16:14). It is a mitzva that usually finds its contemporary halakhic expression in physical (over-)indulgences e.g. food (Orah Hayim 529:1), alcohol (ibid.), fashion (529:2), and travel to Israel (Yerushalmi Hagiga 75d 1:1, Tosafot Hagiga 2a, see R’ Shimshon Nadel). Obviously there are ways to enjoy all of these things appropriately and in the proper moderation, but I hope equally as obviously, the celebration of the holiday and our expression of joy must transcend these physical indulgences.
Another avenue through which diaspora Ashkenazi Jews express this happiness is finally taking the opportunity (only 13 times per year!) to perform a mitzva that is really incumbent daily—for the kohanim to raise their hands and recite birkat kohanim (Rambam, intro. to Hikhot Tefila) and for the assembled congregation to hear and receive that blessing (Sefer Haredim 4:18, Beur Halakha 128). The rationale behind the origins of its customary omission, despite our general desire to perform as many mitzvot as possible as often as possible, is much debated (cf. Orah Hayim 128:44, Arukh Hashulhan 128:63-64), but most theories mention a desire on the part of the kohanim to be permeated with a strong sense of happiness when giving the blessing. It would have been impossible for a working-man to achieve the necessary sense of bliss any time other that the holidays.
I was recently asked, if we diaspora Ashkenazim avoid inviting the kohanim to pronounce the blessing until the holidays when we are commanded to be happy i.e. Yom Tov, why do we not have them say it on hol hamoed as well.
I think that in the experience of most contemporary American Orthodox Jews, the period of hol hamoed presents serious challenges to their ability to feel fully permeated with the happiness that halakha requires. The preparations necessary for the celebration of the week-long hagim which usually include laundry, shopping, cooking, cleaning, hosting, scheduling, and childcare are incredibly demanding. In addition, the inflexibility of many people’s jobs and their vacation policies make it so that the permissions under halakha to work during hol hamoed (work that has a pressing deadline, or which for ignoring it one will incur a major financial loss, cf. Orah Hayim 533, 536, 537) which were originally conceived of as accomodations for rare circumstances have come to apply to a larger percentage of people’s regular work. In ends up that besides all the additional preparations, people do not even have the entire week off to celebrate.
My gut tells me that this contemporary experience is not new. Of course the modern economy and the range of professions common among observant families have changed the dynamic somewhat, but I think that even centuries ago, when the minhagim surrounding the recitation and omission of birkat kohanim developed, many people were struggling with the same types of work/life balance and felt the need to work on hol hamoed for a variety of defensible reasons. I think that the omission of birkat kohanim on hol hamoed speaks to this exact problem, and I hope it provides some consolation for the modern family to know that we are not the first ones who can find it difficult to fully immerse ourselves into the joy and celebration of the holidays; our ancestors struggled with this too and they enshrined their struggle in the minhagim that they passed down to us today.
Further, on the holidays when our time is stretched thin, I hope that we can still scrape together the time and the peace of mind to really rejoice, to experience the mitzvot of the sukka, lulav, matza etc. and the mitzva to celebrate as Hakadosh Barukh Hu intends, and to channel that happiness into the mitzva of birkat kohanim, and the weeks ahead.