Yeah.. I agree. When Enterprise first aired, I quit watching halfway through season 2 in disgust. It wasn't until years later when I just happened to see the SyFy channel airing the Augments arc in season 4 that I thought hey this is pretty cool and gave it another chance. Which years of non-Trek had softened me to it.
There really was no over all plan... a Temporal Cold War, leaving alone how overused and cliched time travel is in Trek, needs careful planning. It could have been cool if done right. But there was no plan except to say, let's screw with the timeline whenever. I can't take a cliffhanger about rewritten history seriously since... we know it won't amount to anything. Then you just have Ferengi, Borg and Romulan episodes thrown in there for no other reason that... he we can and it'll be neat! Right... Archer must be the most boneheaded record keeper ever... which is quite possible being how they blundered around on those scientific missions. It would be like Neil Armstrong saying... "Hey, Houston, we crashed on the Moon. What do you want us to do now?" Ugh.. just never could get sold on the characters, and by the time most of them finally found themselves... the damage was done.