The "game suitable for competition" is not black and white. Games may be tweaked mechanically, by bypassing switches or by rules adjustment to tone down what would otherwise be an issue.
People should distinguish between high level competition and the more common level. A lot of the games under concern are fine in most competitive settings.
Also, the term "exploit" should be used with care. There is a difference between straight bugs. And a non-obvious, perhaps risky and perhaps monotome path to points.
Major concerns are bugs that randomly or even semi-randomly dooms a player from winning the game. Or bringing an unfair battleground. As well as silly scoring that skeews the luck/skill balance way off, and cannot be had in a competition setting.
Further concerns are game progress, jackpot values etc. that are shared between players or even between games. Sometimes rediculous, and sometimes fun and games. Again, not black and white.
The concern of long playing games and repetitive shot strategies is really not an issue with competition play in general. It is an event concern. Stamina games require skill to execute well on. But long playing times are hard to deal with. So TD's may choose to not use such games.
Same goes for the plunge-over, repetitive video mode strategies, modes timeout and likewise not-much-flipping-here play. TD's may find this not suitable, too little pinball action, too long playing times or whatever. And abandon those games.
BTW. Just released, a software mod for The Getaway, that resurrects it for competition play.