They are probably pointing out that there could be a better way to kill/remove/move the urchin without releasing the spawn.

Although it's very hard to get them off their spot and handling them.

Why not combine reducing their number with supplying a "new" market for those who enjoy eating them? https://triedandsupplied.com/saucydressings/how-to-eat-sea-u...

NZ has a similar problem with urchin ("Kina", in NZ) barrens. The urchins in NZ urchin barrens, as in CA, are malnourished and are subsequently difficult and unproductive to eat as they contain very little actual meat.