Passive items have a lower drop rate?

[B. Comet [VF4-A]]

I love this game, but something that makes me kinda "mad" is the absurdly lower drop rate of passive items. For example, I got to ♥♥♥♥♥♥♥ bullet hell and fought the Lich carrying A LOT of different guns but only 1 passive (and it was a movement speed one) and another which I bought from the shop.
If I am lucky enough, I can get the maximum of 3 passive.

[1337Walrus]

It's a quirk with item chests -- every floor's two chests have one gun and one passive/active. If you haven't picked up a gun on that floor, killing the boss forces a gun drop from them.

You'd need to open the gun chest before killing the boss to get the most passives in a single run.

[Hand's Hermit Permit]

Get more chest unlocks to get more passives. Take rogue maybe. His discount, and maybe even stealing or loot bag will give you money to buy more passives from shops.

Boss loot can be anything from garbage to very very good, and the regular shop usually sells junk, so buy keys and try to unlock the gun chest before it. If you get the passive chest first, you already got a passive, so be thankful.

Consider going through secret chambers for more loot. First secret chamber is easy to clear and it's a whole floor of loot and coins.

[Shiro]

Its not like passives have "lower"drop rate. Its just that their drop rate is always "low", considering you can carry and use nearly all passive items at the same time (unlike actives, which you can carry maximum 4 of, and guns, which you can use limited amount of at once).