Well, for me i think thats their strategy to the gamblers to try those different slot machines, to tease you and make you play! and its up to you if you choose to be disturbed or focus, when im gambling im focusing on my game and luckily i won and earn. and for making them an organization to categorize the slot machine is not gonna happen, that's not their point of goal.
Well, some gamblers will not feel disturbed, but they can get tempted to try the other gambling games. Only some gamblers who can stay focus on the games, and they don't feel anything, even if many things show up in front of them.
At times too much options also helps because out of those say you played 10 and one of them might become your favourite and you would want to play more of it. This will make the sites richer as more you play higher the chances of you losing it than vice versa. Every user who comes to site might want to play some or other looking the individual choice.
That is what we will get if we can not control ourselves in any gambling games, and that is not just happening in slots games. No matter if we play 10 or even more, we only have a chance to lose than to win, so we need to manage our money and ourselves.