I actually don't think the mums and dad need worry. It feels...

I actually don't think the mums and dad need worry. It feels like Allegro and Jason Murray are for whatever reason motivated sellers. The takeover allows any motivated large seller to exit in an orderly fashion. Allegro probably sees other investment opportunities and needs to liquidate the holding (they are a private equity fund without a source of capital inflow).
The way it reads is that they don't want to de-list but if shareholders capitulate they will go that way. Blundy would be happy with a controlling interest of 55% and is a capable retailer.
I agree not the best of optics, but Allegro and Murray couldn't exit without cratering the shareprice, Blundy is providing the opportunity but has also negotiated a sharp price.