I think you might be confusing two games sharing the same genre with one game ripping another off. How many 2d, projectile-based fighters do we have now? Yeah... mk didn't rip off sf.... it was simply the second game in that genre, with sf2 being the first.
I also think you are confusing fun gameplay with bad gameplay. Likewise you are confusing frastratingly precise gameplay with good gameplay.
Let's put it this way.... There are some people that say robotron is better than smashtv. Those people say so because robotron is such a hard game that people have tournaments and marathon sessions just to prove how skilled a gamer is. This does NOT make robotron a superior game, it just makes it a more challenging one. Some people (myself included) would say that it is challenging to the degree that it is no longer fun.
On the other hand, smashtv has everything else going for it. Better graphics, a more interesting storyline, a larger variety of enemies and weapons, ect...
But admittedly it is easier than robotron and you can probably play through it in a couple of hours. Anybody can play a decent game of smashtv though, and pretty much everyone that does will enjoy it, UNLIKE robotron.
And then there are guys like you, who would dismiss smashtv because robotron came out first. This is lame argument man. Gradius was the first of it's kind. It invented an entire genre of space shooters and there are are least two dozen franchises out there. You know what? I've yet to find a really terrible game in the "gradius" genre and most are as good if not BETTER than gradius. This is because konami has been releasing the same game with a different coat of paint since 85, while the genre it created has been evolving.
This is the SF vs MK debate in a nutshell... one is for fighter nerds that insist on every game being so overly complex that the average joe will get his ass handed to him and never play again...the other is for people that like games that are fun, fun to play with other people and are constantly evolving.... i.e. no "mk2 turbo hyper edition 2k13".