Sure it would be best to build the tunnels away from civilian infrastructure but there's barely any away-from-civilian-infrastructure places in the Gaza Strip.
What would be even better, IMHO, is if Israel just stopped murdering Gazans.
The tunnels are on a depth of 18-25 meters. Apart from the 2000lb bombs, there is nothing that will destroy a reinforced tunnel that deep. If even that. It will however destroy sewage and water infrastructure.
One of those bunker busters will also do immense damage to surrounding structures. Gaza is one of the more densely populated areas on earth. You don't use 2000lb bombs without causing a lot of death and damage outside of the thing you a re targeting.
Not only that, every time hospital attacks were justified bt "Hamas underground conplexes" the evidence has been lacklustre or even completely absent. They demolished the only specialist cancer hospital in Gaza claiming it was used as a command central for Hamas. But still no evidence has been provided. The only thing we DO know is that the IDF had used the hospital as a base before denolishibg it.
While I don't doubt that there are examples of Hamas using civilian infrastructure (and this v.civilians) as shields, the Israeli usage of the term is a poor excuse for indescriminate bombing of apartment buildings, schools and hospitals.
