Donations of services don't qualify under current law. That's not unique to Canada. There are probably some good reasons for that, at least one of which is the potentially highly significant revenue implications of recognizing donations of services, in the sense that people aren't bound, given the scarcity of their time, to donate in the same way as they're bound by scarcity of financial resources or property.
One of the other difficulties is there's generally a principle that you find in the cases, although it's not always articulated as bluntly, and that is we generally don't like to recognize donations that are difficult to value. That's one of the fundamental problems with recognizing donations of services as tax-receiptable gifts. If that's something the committee wants to look at, it would best be done as a separate regime, rather than piggybacking on the current one, which would require a valuation of the service contributed.
Those are reasons why this jurisdiction and others historically haven't recognized those kinds of donations.