Totally fine with me. Blue-Eyes has too much Synergy with cards it has nothing to do with. There is a stupid recent trend where BE players keep summoning "Crystron Quarion" in 1 turn with level down and Priestess + Maiden.
They should not have access to other decks' boss monster because this is unfair.
They have other ways to stall. Ballista is a trap meant for decks that fill the field quick, you can't put it in just every deck. Simply having regular backrow removal in your deck against 3 infinite attack negates is not enough.
Cope. Some decks have it easier than others. Ballista Salad is advisable for the ones that run monsters that get the special summon effects even if floodgated. A lot of decks take longer and have more trouble swarming if their key cards get hit before they can activate their effects on the field.