I can feel your pain, but without those scenarios you would very rarely cap an enemy-base in a random bg, because you see everything and everybody coming to a base.
Thats where strategy comes into play, because thats what pvp in general and especially battlegrounds are made for - Teamplay; never ever ever defend a base alone, unless you're one of the classes mentioned above. Or let somebody at least be near enough to spy a stealthtap and help.
The 'Problem here isn't the cap-time, neither it is the benefit from invisibility and spammable CC. It is the mindset of most players in random pvp and their silly, stupid, mindf*cked decisions.
Just join a random BG and take a look at the map the whole time if you want something to laugh (or desparately cry).
And never forget: What's a disadvantage for YOUR team can also be used against the ENEMY team.