Why I can't accept quest that I could do alone or with second adventurer

Cause they are guild quests, they not meant for solo "guilds".

I feel you.  I'm in a few player "guild" consisting of my siblings, who really aren't dedicated to this game right now (real progression is too onerous for them, the art is going backwards, confused/confusing storyline, etc.).  But, guilds are supposed to be large social groups, so requirements are based on lots of player activity.  It's an amazing thing being part of a large group who feels and plays the same way you do, so I see why they push this.  If you can, join a larger guild, or get busy recruiting!

Best of luck!

Also add a role in the guild to accept these quests. Tired of asking in chat every single time for an officer, tired of different servers having different quest. Its simply retarded. Almost as garbage as the atoraxxion main quest which (im doing right now as you can fucking tell from my great mood) is absolutely garbage and the devs should be fucking embarrassed and depressed for releasing that dogshit without trying it once.

this was just added to glab this week so expect that to be added to na/eu in 2 weeks

Actually there is really no reason this minimum is in place. For example if you and a friend start a guild so 2 people and want to get all the base buffs before trying to grow you can't. Also even if you in a guild by yourself the small quests don't payout much and you can't do guild payouts. So honestly this restriction of having 3+ people online is useless. You also can't collect daily pay over 1mil unless you have 10 people online. So yeah they should at least remove the 3 people minimum online to do quests. It would help fresh quilds with a handful of players get buffs done and still make guild progress until they can get enough people.