They are two different things - deposit is just in case of minor accidents etc... If you don;t have one, then you won't be able to claim (for example) for a broken mirror.
In broad terms the Host Guarantee/Protection is in the event of signficant damage to your accommodation by a guest.
The only people who will be put off booking if there is a security deposit are probaby the guests you don't want - remember they don't actually pay this deposit, it's just an authorisation against their credit card in case of damage.