I can't see the forest because all those trees are in the way!
Bad players don't make the game difficult for AP's at all... they make it POSSIBLE! You NEED those crazy and stupid players in place emptying their wallets and playing in a manner that gives the casinos a much higher house advantage to keep them in business and content with their profitability, plain and simple. No profits means no reason to have the game! If every single player adhered to proper basic strategy and played conservatively, there would be little in it for the casino. Some of those "hunch luck crazy" players making horrific strategy and betting errors fill in the gaps for profitability!
It's not 1980 anymore and as it is the casinos have altered procedures and rules to whatever extent they can get away with to increase profitability and eliminate AP issues. An AP that was using some very basic counting method and turning a nice profit in 1980 would be up against a brick wall in today's games and would go broke in a hurry! It's just not like it once was. AP's are no longer any threat to the casinos, primarily because the procedural and rule changes have rendered the vast majority of games unplayable to begin for an AP. These days, you have to not only shop around for what games you play but employ advanced techniques and tactics flawlessly to gain just the tiniest bit of advantage with today's games. How many people can do this? Not very many...
When you see someone making disastrous strategy errors, betting irresponsibly, using some luck and hunch method rather than any common sense, etc... commend them, be grateful for them, feel blessed to have them around because they are insuring profitability for the casinos. Profitability means not having to jack up the house advantage beyond what they've already jacked it up to. The game has already become tough enough! Having enough of these sorts of players onboard possibly means having the game in place to begin with.