The mortgage interest deduction is bad. Economists are almost universal in their agreement on this topic. Sure it sucks that some people got to take advantage of a bad thing in the past, but that isn't a good argument for keeping it around just for the sake of generational fairness.
That’s just one facet, I don’t think that’s the only reason to keep it around. I think it’s irresponsible economics to encourage an economic behavior and then to uproot it abruptly. I think the knock on effects on the housing market and rental markets haven’t been appropriately priced in. I think there’s a lot of ways for this to go sideways and the payoff isn’t that great.
Couple that to the estate tax changes which are not an economic driver and help to curb wealth inequalities and I think it’s a raw deal.