Board Game Arena

If they join an open table and then refuse to start, in my opinion, that's a reportable offense.

It can happen every once in a while, if you realize that the table settings are not what you expected, or that you won't have time to finish the game, or you get a call. But if it happens repeatedly, that player is simply annoying you, and wasting your time (consider, for example, that you could have open tables at several games, waiting for opponents, and this action automatically closes all the other tables and forces you to reopen them).

A different thing is if the problematic player has an open table, you join them, and then they refuse to start. They have the right to decline to play with specific players for whatever reason. But if they join an existing table, they know who they're playing with before joining.

Has this got anything to do with Automatic mode?
Do they automatically join your table, but then decide they don't want to play with you?

This usually happens to me in Manual mode. I decline games all the time in Automatic mode when the risk/benefit is skewed against me points wise, like everybody else does!

Automatic mode and manual mode are basically the same. If you have a manual table open and someone else queues automatically while fitting all the criteria of your table they will join it "automatically". If you have a manual table open and this person is joining and then declining to start it's likely they were queueing automatically.

Personally I find it annoying when anyone declines a game because their opponent's ELO is too low or too high. There are settings in place to prevent this, just change your settings and stop wasting everyone's time.

Yes.
I think there should be an option in the manual mode table settings to not allow Automatic mode people to join the table.
It seems Auto mode > Manual mode.

It is also a problem for a manual table in a couple more ways:

1.
Automatic mode people instantly join and leave manual tables and you get the 'are they in or out feeling'. You can't have a discussion with them before the game because they are not really there. The game starts and they don't accept because they've already started on a different game / table.

2.
Play with a group of friends invited, someone decides they don't want to play. You cannot change the number of players once the table is open, and you have to go through the 'open table' then 'start game' clicks and in the split second in-between rando-non-friend joins the table because of automatic mode. You then have to stop the game, kick the person and hope it doesn't happen again, which it probably will...or restart the whole table shenanigans.