TLDR at the bottom.
I don’t think the developers understand some players like to play this game casually, as much as they say they do. It’s mainly because everyone has different definitions of casual play. What does casually actually mean and how does everyone interpret it?
Committed play vs. Uncommitted play
Playing this game really boils down to the two points above, are you currently playing the game with committed attention, i.e. raiding or group pvp, or are you playing with uncommitted attention, i.e. questing, farming, pug content. Committed play can also include future date scheduling, i.e. joining a raid group and telling people “Sorry, I’m unavailable every Tuesday and Thursday evening 7-11PM.”
Typically your casual players aren’t committing time to the game. Blizzard usually tries to alleviate this creating more solo content or reducing entry cost to the content that requires the most committed play. While this allows those with the uncommitted time to experience all the content, it sometimes minimizes the time investment those that played with put in.
Why am I even explaining this all when the title is about guilds?
Guilds want committed play. If you can’t commit to a schedule typically you’ll find yourself out of a raid spot. Whether that’s in the form of a bench or out indefinitely, sometimes a guild is not the answer for people who still want to engage with the community but aren’t trying to overcommit their play time.
As a prior raid lead, it’s always a double edged sword with the committed play. Do I expect everyone to show up to every raid? No. But how much do I over recruit and when we have to sit people how do those conversations go? People want to play the game, and “just finding a guild” isn’t the answer for people aren’t trying to raid every week. You can’t expect to just have a raid spot for being in a guild either, that’s dumb too. If you want to have a spot in the raid, the team usually likes to know ahead of time since they’re already committing that time.
Having a strong pug scene is very healthy for the game. I can now commit a few hours to a raid when I have the opportunity, versus planning ahead days of the week. Gnomeregan is getting really boring. But if I take a break for a week or two I’m massively hindering my guild and the current roster. And if I take a break, that implies I’m coming back, how does the raid leader manage my return along with a roster that he had to fill in order to continue raiding? God forbid he would decide to have the group take a break, as any raid lead knows that’s a death sentence usually for future endeavors.
TLDR; Just joining a guild is not the best option for an mmo. The community should thrive even outside of the small internal cliques.