By this poll's results it's only 1 in 5 who really didn't like it. Not that big a number. There were things I disliked about the movie and most of then are "could have done better" things. Overall I've been thinking about the movie a lot since I saw it and there's plenty to discuss. Once Americans start seeing the film check those boards and you'll probably find more vocal love.
For example of a could have done better. The morphing cubes. Something TF technology can't do, but humans can produce? Unlikely. But it would have made sense that Lockdown and his crew, travelling all over the galaxy, had that ability instead. Keep the effect in the film (if you must) but give it to the characters most likely to have it.
You know what human-built Transformers should have looked like? Diaclone. Imagine if in the 30th anniversary of Transformers we saw a movie with transforming robots that were a bit blocky, had visible seems and looked like the toys that started this all. Have hundreds of these mass produced robots so overwhelming numbers make up for disadvantages in speed and mobility. Give some Diaclone designers a cameo in the lab. And then have Lockdowns morphin crew as the additional threat.