One thing that I've always wanted to be able to do in Worms games is to bring up my inventory while it's my opponent's turn. Mainly it'd be to prepare for my next turn, since I typically don't always have a photographic memory of all the items I have and how many of each. Also, it's 'cause sometimes I'd like to kill time that way rather than watch my opponent, especially when they're just standing around taking forever to figure out what to do.

We've been able to do that on Worms Armageddon for literally years now. :p

Didn't you use to play on WormNet1?

I never played any of the PC games online, only locally with friends, and even then it's been well over a decade since. I don't think I ever even played Armageddon. I've never really been a PC gamer, so it wasn't until recent years that I really got back into Worms (and even though that started up again w/ the 3D games last gen, I thankfully still kept my interest in the series to really get back into it with the XBLA games).

So I guess that begs the question of why'd they remove a feature which already existed in past installments.

So I guess that begs the question of why'd they remove a feature which already existed in past installments.
No, no.
The feature to always view your weapons panel has only been added to Worms Armageddon in the v3.6.28.0 Beta Update from 29.06.2007.